Operation Michael

Operation Michael was a First World War German military operation that began the Spring Offensive on 21 March 1918. It was launched from the Hindenburg Line, in the vicinity of Saint-Quentin, France. Its goal was to break through the Allied lines and advance in a north-westerly direction to seize the Channel ports, which supplied the British Expeditionary Force (BEF) and to drive the BEF into the sea. Two days later Ludendorff changed his plan and pushed for an offensive due west, along the whole of the British front north of the Somme. This was designed to separate the French and British Armies and crush the British forces by pushing them into the sea. The offensive ended at Villers-Bretonneux, to the east of the Allied communications centre at Amiens, where the Entente managed to halt the German advance; the German armies had suffered many casualties and were unable to maintain supplies to the advancing troops.

Much of the ground fought over was the wilderness left by the 1916 Battle of the Somme and the battle has sometimes been called the 1918 Battle of the Somme or by the French as the Second Battle of Picardy (2ème Bataille de Picardie). The failure of the offensive marked the beginning of the end of the First World War. The arrival in France of large reinforcements from the United States (US) replaced Entente casualties but the German Army was unable to recover from its losses, before these reinforcements took the field. Operation Michael failed to achieve its objectives and the German advance was reversed during the Second Battle of the Somme (21 August – 3 September) in the Allied Hundred Days Offensive.

Strategic developments
On 11 November 1917, the German High Command (Oberste Heeresleitung (OHL) discussed what they hoped would be a war-winning attack on the Western Front the following Spring. Their target was the British Expeditionary Force (BEF), which they regarded as exhausted by the battles in 1917 at Arras, Messines, Passchendaele and Cambrai. A decision to attack was taken by Ludendorff on 21 January 1918 At the start of 1918, the German people were close to starvation and growing tired of the war. General Erich Ludendorff, in command of the German armies, realized that he had a fleeting chance to win the war. By mid-February 1918 he had moved nearly 50 divisions from the east following the Russian surrender and the Treaty of Brest-Litovsk which gave his forces a numerical advantage on the Western Front. Germany had 192 divisions and three brigades on the Western Front by 21 March. divisions in France and Flanders, out of a total of 241 in the Army. Of these, 110 were in the front line, including 50 which faced the short British front. A further 67 were in reserve, including 31 facing the British Expeditionary Force (BEF). However, American soldiers were on their way to Europe. By May 1918, 318,000 American soldiers would be in France, with another million planned to arrive before August. The German authorities knew their only realistic chance of victory was to defeat the Allies before the human and material resources of the United States could be deployed.

The German strategy for 1918 Spring Offensive or Kaiserschlacht (Kaiser's Battle), a series of attacks that achieved the deepest advances along the Western Front by either side since 1914. The four German attacks had the code names Michael, Georgette, Gneisenau and Blücher-Yorck. Ludendorff's first and main attack, (Michael), was on the Somme. There were subsequent diversionary attacks against the British (Georgette) at the Lys and at Ypres which were planned to confuse the enemy and Operation Blücher against the French in the Champagne region. Although British intelligence knew an operation was being prepared, this-far reaching plan was much greater than Allied commanders envisaged. Ludendorff aimed to cut through on the Somme, then wheel north-west to cut the British lines of communication behind the Artois front, trapping the BEF in Flanders. This would draw forces away from the Channel ports, that were essential for British supply and then the Germans could attack these ports and other lines of communication. The British army would be surrounded with no means of escape, which would lead to surrender. The thrust of this simple strategy was weakened and unbalanced during planning.

The British Prime Minister, David Lloyd George, had agreed to take over this area at the Boulogne Conference, against military advice, after which the British line was extended. In reality, this "line", taken over from the French, barely existed, needing many man-hours of construction work to make it easily defendable. Unfortunately, sufficient man power was not available. During the winter of 1917–1918, the new British line was established in an arc around St Quentin, by many small unit actions among the ruined villages in the area. This line differed from the rest of the British front as the line of trenches was not complete. There were many isolated outposts, gaps in the line and large areas of disputed territory and waste land. These positions were slowly improved by building the new three-zone system of defence in depth but much of the work was performed by infantry working-parties. Most of the redoubts in the battle zone were complete by March 1918, the rear zone was still under construction.

The British Army had undergone a drastic reorganization to cope with the manpower shortages. A British infantry division was now nine battalions strong, reduced from four battalions to three per brigade. It had been laid down that the senior (regular and first-line territorial) were to be retained in preference to the higher-numbered second-line territorial and New Army battalions. Consequently, second-line territorial and New Army divisions were badly disrupted, having in some cases to disband half of their battalions to make way for units transferred from regular or first-line territorial divisions. Battalions had an establishment of 1,000 men but some had fewer than 500 due to battle losses and sickness during the cold winter months.

Tactical developments
Tactically, the German army adopted an approach that had succeeded on the Eastern Front, particularly at the Battle of Riga in 1917. The Germans had developed elite units following infiltration tactics, trained to infiltrate the enemy's front line. Stormtroopers (Stoßtruppen) were to lead the infantry attack, operating in groups that advanced quickly by exploiting gaps and weak defenses. The stormtroops would by-pass defended areas, which follow-up infantry units could deal with once they were isolated. The stormtroops were expected to occupy territory rapidly so as to disrupt communication by attacking enemy headquarters, artillery units and supply depots in the rear. Each division transferred its best and fittest soldiers into storm units, from which several new divisions were formed. This process gave the German army an initial advantage in the attack but meant that the best troops would suffer disproportionate casualties, while the quality of the men in reserve declined.

Developments in artillery tactics were far more influential than infantry infiltration tactics. Ludendorff abandoned the massive bombardment of enemy infantry in the forward trenches which took away the element of surprise. A hurricane artillery bombardment concentrated on artillery and machine-gun positions, headquarters, telephone exchanges, railways and communication centres. There were three phases to the bombardment: a brief attack on the enemy's command and communications, then destruction of their artillery and lastly an attack upon the enemy front-line infantry defenses. This very deep bombardment aimed to knock out the British ability to respond; it lasted only a few hours to retain surprise, before the infantry attacked behind a creeping barrage. Such artillery tactics became possible due to the vast numbers of accurate heavy artillery and ammunition, which Germany had deployed on the western front by 1918.

An officer of the 51st Division wrote,

"'The year 1917 ... closed in an atmosphere of depression. Most divisions on the Western front had been engaged continuously in offensive operations ... all were exhausted ... and weakened.' The last German offensive on the Western Front, before the Cambrai Gegenschlag (counter-stroke) of December 1917, had been against the French at Verdun, giving the British commanders little experience in defence. The development of a deep defence system of zones and trench lines by the Germans during 1917, had led the British to adopt a similar system of defence in depth. This reduced the proportion of troops in the front line, which was lightly held by snipers, patrols and machine-gun posts only and concentrated reserves and supply dumps to the rear, away from German artillery. British divisions arranged their nine infantry battalions in the forward and battle zones according to local conditions and the views of commanders; about ⅓ of the infantry battalions of the Fifth Army and a similar number in the Third Army held the forward zone."

The Forward Zone was organised in three lines to a depth depending on the local terrain. The first two lines were not held continuously, particularly in the Fifth Army area, where they were in isolated outpost groups in front of an irregular line of supporting posts. The third line was a series of small redoubts for two or four platoons. Posts and redoubts were sited so that intervening ground could be swept by machine-gun and rifle-fire or from machine-guns adjacent to the redoubts. Defence of the Forward Zone depended on fire-power rather than large numbers of troops but in the Fifth Army area a lack of troops meant that the zone was too weak to be able to repulse a large attack. The Battle Zone was also usually organised in three defensive systems, front, intermediate and rear, connected by communication trenches and switch lines, with the defenders concentrated in centres of resistance rather than in continuous lines. About 36 of the 110 infantry and pioneer battalions of the Fifth Army held the Forward Zone. Artillery, trench mortars and machine-guns were also arranged in depth, in positions chosen to allow counter-battery fire, harassing fire on transport routes, fire on assembly trenches and to be able to fire barrages along the front of the British positions, at the first sign of attack. Artillery positions were also chose to offer cover and concealment, with alternative positions on the flanks and to the rear. About ⅔ of the artillery was in the Battle Zone, with a few guns further forward and some batteries were concealed and forbidden to fire before the German offensive began.

German offensive preparations
The Germans chose to attack the sector around St Quentin taken over by the British from February–April 1917, following the German withdrawal to the Hindenburg Line. Germany had begun construction of the Siegfried Stellung (Hindenburg Line) in September 1916, during the battle of the Somme. It stretched over 300 mi from the Channel to the Moselle River and was built by Belgian and Russian prisoners of war. The strongest section was the salient at St. Quentin between Arras and Soissons. The line was 1 mi deep with barbed wire in zig-zag lines of 50 ft, protecting three lines of trenches, interconnecting tunnels and strong points. In the rear were deep underground bunkers known as stollen (galleries) and artillery was hidden on reverse slopes. The Germans withdrew to this line in an operation codenamed Alberich over five weeks, during which time German High Command ordered a scorched earth policy. The ground abandoned in the retreat was laid waste, wells were poisoned, booby-traps laid and most towns and villages were destroyed.

German plan of attack
The attacking armies were spread along a 43 mi front between Arras, St. Quentin and La Fère. Ludendorff had assembled a force of 74 divisions, 6,600 artillery pieces, 3,500 mortars and 326 fighter aircraft, which were split between Otto von Below’s Seventeenth Army, Georg von der Marwitz’s Second Army, both of which were part of the Army Group commanded by Rupprecht, Crown Prince of Bavaria, and General Oskar von Hutier's Eighteenth Army, (part of the Army Group commanded by Crown Prince Wilhelm) and the Seventh Army. The main weight of attack was between Arras and a few miles south of St-Quentin. Von Hutier's Eighteenth Army, headquartered at Guise, boasted 27 Divisions. Forty-four divisions were allocated to Operation Michael and called "Mobile" divisions, which were brought up to full strength in manpower and equipment. Men over 35 were transferred, a machine-gun unit, air support and a communications unit were added to each division and the supply and medical branches were re-equipped; a chronic shortage of horses and fodder could not be remedied. Around the new year the Mobile divisions were withdrawn for training according to "The Offensive in Trench Warfare". Training emphasised rapid advance, silencing machine-guns and maintaining communication with the artillery, to ensure that infantry and the creeping barrage moved together. Infantry were issued with light machine-guns, mortars and rifle grenades and intensively trained. Thirty divisions were trained in the new tactics but had a lower scale of equipment than the elite divisions and the remainder were stripped of material to supply them, giving up most of their remaining draught animals.

In the north, two German armies would attack either side of the Flesquières salient, created during the battle of Cambrai. The Eighteenth Army, fresh from the Eastern Front, planned its attack on each side of St. Quentin, aiming to sever British lines and divide the British and French armies. The two northern armies would then attack the British position around Arras before advancing north-west, to cut off the BEF in Flanders. In the south, it was intended to reach the Somme, and then hold the line of the river against any French counter-attacks. During the planning process, the southern advance was extended to include an advance across the Somme. The success of this southern advance would badly unbalance the entire offensive.

British defensive preparations
In the north General Julian Byng commanded the Third Army, defending the area from Arras south to the Flesquières Salient. To the south General Hubert Gough and the Fifth Army held the line down to the junction with the French at Barisis. Byng had commanded the Canadian Corps who took Vimy Ridge at the Battle of Arras (1917) and the Battle of Cambrai (1917) and Gough had commanded the Reserve Army (renamed the Fifth Army in October 1916) which had taken over part of the Somme battlefront in July 1916. The Fifth Army held the longest front of the BEF with twelve divisions and three cavalry divisions, 1,650 guns, 119 tanks and 357 aircraft. An average British division in 1918 consisted of 11,800 men, 3,670 horses and mules, 48 artillery pieces, 36 mortars, 64 Vickers heavy machine guns, 144 Lewis light machine guns, 770 carts and wagons, 360 motorcycles and bicycles, 14 trucks, cars and 21 motorized ambulances.

In the Weekly Intelligence Summary of 10 March 1918, British intelligence predicted a German offensive in the Arras–St. Quentin area based on air reconnaissance photographs and the testimony of deserters; the prediction was reiterated in the next Summary on 17 March. Allied aircraft had photographed German preparations behind their lines. New supply roads had been constructed and shell craters had been turned into concealed trench mortar batteries. Heavily laden motorized and horse-drawn transports had been seen heading into St. Quentin from the east, and in the distance German officers were observed studying British lines. The British answer was increased nightly bombardment of the German front lines, rear areas, and possible areas of troop assembly. A few days before the attack, two German deserters wanting to avoid the coming offensive slipped through No Man's Land and surrendered to the 107th Brigade. They spoke of troops, batteries of artillery and trench mortars massing on the German front. They reported massed trench mortars directly in front of 36th Division lines for the purpose of cutting their wire and an artillery bombardment, lasting several hours, as a preliminary to an infantry assault.

The 9th Irish Fusiliers' War Diary describes their activities from 18–20 March as being intensive training during the day, with specialist training in the evening. During the night of 20 March, troops of the 61st Division launched a raid on German positions and took more prisoners, who told them that the offensive would be launched the following morning. The Fifth Army defences which were still incomplete, the Rear Zone existed as outline markings only and the Battle Zone consisted of battalion "redoubts" that were not mutually supporting and vulnerable to German troops infiltrating between them. The British reacted upon the information gained from the 61st Division's prisoners, ordered an intermittent bombardment of German lines and likely areas of assembly for attack at 03:30 and a gas discharge on the 61st Division front. At about 04:40 a huge German barrage began along all the Fifth Army front and most of the front of the Third Army.

Day 1, 21 March
The artillery bombardment began at 04:40 with an intensive German barrage opened on British positions south west of St Quentin for a depth of 4 - 6 km. At 04:35 a heavy German barrage began along a 40 mi front. Trench mortars, mustard gas, chlorine gas, tear gas and smoke canisters were concentrated on the forward trenches, while heavy artillery bombarded rear areas to destroy Allied artillery and supply lines. Over 3,500,000 shells were fired in five hours, hitting targets over an area of 150 sqmi; this was the biggest barrage of the entire war. and hit the British front occupied by Fifth Army, most of the front of Third Army and some of the front of the First Army to the north. The front line was badly damaged and communications were cut with the rear zone, which was severely disrupted.

When the infantry assault began at 09:40, the stormtrooper tactics had mixed success, the German 17th and 2nd armies were unable to penetrate the Battle Zone on the first day but the 18th Army adanced further and reached its objectives. Dawn broke to reveal a heavy morning mist. By 05:00, visibility was barely 10 yd in places and the fog was extremely slow to dissipate throughout the morning. The fog and smoke from the bombardment made visibility poor throughout the day, allowing the stormtroopers to penetrate deep into the British positions undetected. Much of the Forward Zone fell during the morning as communication failed; telephone wires were cut and runners struggled to find their way through the dense fog and heavy shelling. Headquarters were cut off and unable to influence the battle.

Around midday German troops broke through south-west of St Quentin, reached the Battle Zone and by 14:30 were nearly 3 km south of Essigny. Gough kept in contact with the corps commanders by telephone until 15:00 then visited them in turn. At the III Corps headquarters (HQ) he authorized a withdrawal behind the Crozat canal, at the XVIII Corps HQ he was briefed that the Battle Zone was intact and at the XIX Corps HQ found that the Forward Zone on each flank had been captured. Gough ordered that the ground was to be held for as long as possible but to withdraw the left flank to maintain touch with the VII Corps. The 50th Division was ordered forward as a reinforcement for the next day. On the VII Corps front Ronssoy had been captured, against which the 39th Division was being brought forward; on the rest of the front, the 21st and 9th divisions were maintaining their positions and the link with V Corps of the 3rd Army in the Flesquières Salient to the north. The Fifth Army's "Forward Zone", the only area where their defenses had been completed before the start of the attack, had been captured. Most of the troops in the zone were taken prisoner by the enemy who moved up unseen in the fog. Although several garrisons in the various keeps and redoubts had put up stern resistance, by now they were surrounded. Many of these inflicted heavy losses on the Germans, despite direct attacks on their trenches with flame throwers. Some surrounded units surrendered once cut off, out of ammunition and severely reduced by casualties; others fought to the last man.

The Third Army had seen important breakthroughs by the enemy in the morning along the Cambrai–Bapaume road in the Boursies–Louverval area, and through the weak defenses of 59th Division near Bullecourt. By the close of the day, the Germans had broken through the British Forward Zone and entered the Battle Zone on most of the attack front and advanced through the Battle Zone on the right flak of the Fifth Army from Tergnier on the Oise river to Seraucourt. South-west of St. Quentin in the 36th Division area, the 9th Irish Fusiliers war diary reported that serious losses had been sustained. In addition to losing the three battalions of the Forward Zone, the three battalions in the Battle Zone were reduced to 250 men each and only the three reserve battalions were at reasonable strength. Casualties in the division from 21–27 March were 6,109 the most costly day being 21 March.

Gough had been forced to order a fighting retreat to win time for reinforcements to reach his army. It was as the British fell back, that troops in the redoubts had been left behind to be mopped up by the following German infantry. The right wing of the Third Army also retreated, to avoid being outflanked. The morning fog had delayed the use of aircraft but, by the end of the day, 36 squadrons of the Royal Flying Corps had been in action and reported losing 16 aircraft and crew, while having shot down 14 German aircraft; German records show 19 and 8 losses. The first day of the battle had been very costly for the Germans, suffered c. 40,000 casualties, slightly more than they inflicted on the BEF. The attack in the north had failed to isolate the Flesquières Salient, which had been held by the 63rd Division and the weight of the German offensive was increased in the south, where the 18th Army received six fresh divisions.

Day 2, 22 March
On the second day of the offensive, British troops continued to fall back, losing their last footholds on the original front line. Thick fog impeded operations and did not disperse until early afternoon. The second day was a collection of many separate, often isolated engagements as the Germans pressed forward and the British held their posts, often not knowing who was to either side of them. Brigades and battalions did not count for much that day. It was a day of stubborn and often heroic actions by platoons, sections and even individuals isolated from their comrades by the fragmented nature of the battle and lack of visibility. The greatest danger facing the British on 22 March was that the Third and Fifth armies might become separated. Byng did not order an abandonment of the Flesquières salient, which his army had won at such cost and Haig had to order him to keep in contact with the Fifth Army, even if that required a further retreat; the day also saw the first French troops enter the battle on the southern flank.

Small parties of British troops fought delaying actions to allow those to their rear to rush into new defensive positions. Some British battalions continued to resist in the Battle Zone and delay the German advance, even managing to withdraw at the last moment. Lieutenant-Colonel Wilfrith Elstob, VC, DSO, MC commanding the 16th Manchesters in the Manchester Redoubt, fought until annihilated. Directly to their rear in support was the 2nd battalion of the Bedfordshire regiment, which was attacked from all sides after the units on their flanks had been pushed back by the German assault, the Bedfords were ordered to retire having lost half their number.

The biggest retreat was made by XVIII Corps, whose commander, General Ivor Maxse, appeared to have misinterpreted an order from Gough for a fighting retreat to mean that he could fall back all the way to the Somme. The Germans brought heavy artillery into Artemps under the cover of the morning mist, which forced the remaining battalions of the 109th Brigade (36th Division) to retreat to join the 108th Brigade at Happencourt. The result of the misunderstanding between Gough and Maxse was that General Nugent's commanders chose Sommette-Eaucourt on the south bank of the Canal de Saint-Quentin (where there was heavy fighting) to form a new line of defence. This required the Division to cross the Canal at Dury. The daylight withdrawal to the Green Line, over almost 9 mi, was completed gradually, assisted by the defence of the Ricardo Redoubt whose garrison did not surrender until 16:40. During the retreat the Engineers blew all the bridges across the Canal between Ham and Ollézy but the railway bridge at Pithon suffered only minor damage. The Germans were soon over the river and advanced up to 10 mi to the Crozat canal.

Day 3, 23 March
Early on the morning of Saturday 23 March, German troops succeeded in breaking through the line in the 14th Division's sector on the Canal at Jussy. The 54th Brigade were holding the line directly to their south and were initially unaware of their predicament, as they were unknowingly being outflanked and surrounded. The 54th Brigade History records "the weather still favoured the Germans. Fog was thick over the rivers, canals and little valleys, so that he could bring up fresh masses of troops unseen". In the confusion, Brigade HQ tried to establish what was happening around Jussy and by late morning the British were in full retreat once again in front of German troops who had crossed the Crozat Canal at many points. All lines of defence had now been overcome and there was nothing left to stop the German advance. Bitter fighting over open country ensued. There was little rest for British troops; who were either fighting, beating a retreat or doing both. During that day Aubigny, Brouchy, Cugny and Eaucourt fell.

Lieutenant Alfred Herring of the 6th Northamptonshire regiment in the 54th Brigade, despite having never been in battle before, led a small and untried platoon in a counter-attack against German forces who had captured the critical Montagne Bridge on the Crozat Canal. He not only won the position back against all odds but held it against repeated attacks for twelve hours before he was captured along with the remnants of his small command. Lieutenant Herring was awarded a Victoria Cross when repatriated after the war.

The remnants of the 1/1st Hertfordshire Battalion were retreating across the southernmost edges of the 1916 Somme battlefield and by the morning of the 24 March there were only eight officers and around 450 men left. The war diary read,

"Before dawn the Bn marched to BUSSU & dug in hastily on the east side of the village. When both flanks became exposed the Bn retired to a line of trenches covering the PERONNE-NURLU road. After covering the 4/5th Black Watch Regt on the left the Bn withdrew to the ST. DENNIS line which was very stubbornly defended. The Bn then retired with difficulty to the line protecting the PERONNE-CLERY road with the remainder of the 116th Inf. Bde. to cover the retreat of the 117th and 118th Inf. Bdes. When this had been successfully accomplished under very harassing machine gun fire from the enemy, the Bn conformed to the general retirement on CLERY village where it concentrated. The remnants of the Bn then defended a line of trenches between the village and running down to the River SOMME.”(23 March 1918)"

Ludendorff implemented the second phase of his battle plan. He issued a directive for the "continuation of the operations as soon as the line Bapaume–Peronne–Ham had been reached: Seventeenth Army will vigorously attack in the direction Arras–St Pol, left wing on Miraumont [4.5 mi west of Bapaume]. Second Army will take Miraumont–Lihons [near Chaulnes] as direction of advance. Eighteenth Army, echeloned, will take Chaulnes–Noyon as direction of advance, and will send strong forces via Ham". Von Below's Seventeenth Army was to roll-up British forces northwards and the Second Army was to attack west along the Somme towards the to the vital railway centre of Amiens. The Eighteenth Army was to head south-west, destroying French reinforcements en route and threaten the approaches to Paris in the Second Battle of Picardy (2e Bataille de Picardie). (The southern armies advanced until the end of March but the offensive to the north-west against the British failed.) The advance had been costly the German infantry and were beginning to show signs of exhaustion; transport difficulties had emerged, supplies and much heavy artillery lagged behind the advance.

Day 4, 24 March
By now, the front line was difficult to establish as the remnants of the divisions of the Fifth Army were fighting and moving in small bodies, often composed of men of different units. Germans units advanced irregularly and some British units ended up under French command to the south or behind enemy lines to the east, making the logistic tasks of the corps and divisional staffs nigh impossible. The Official Historian, Brigadier-General Sir James E. Edmonds wrote,

"After three days of battle, with each night spent on the march or occupied in the sorting out and reorganization of units, the troops – Germans as well as British – were tired almost to the limits of endurance. The physical and mental strain of the struggle against overwhelming odds, the heavy losses, the sinister rumors which were rife, all contributed to depress morale."

The 109th brigade were planning a counterattack in the early hours of 24 March but, before dawn, German troops entered Golancourt, just north-west of Villeselve, so British troops were forced to remain in their defensive positions. The front at this time ran roughly between Cugny and the south of Golancourt. An example of the condition of many British units was the 54th Brigade of the 18th Division, by nightfall on 23 March the 7th Bedfordshire and 6th Northamptonshire battalions had c. 206 men each and the 11th Royal Fusiliers had 27 men, who were hurriedly reorganized and then took post in the wood north of Caillouel at 10:00. The battle continued throughout the morning along the entire front and at 11:00 the remnants of the 14th Division were ordered to withdraw further south to the town of Guiscard. A series of small German attacks that day dislodged the exhausted British troops piecemeal and gaps in the front created by this staggered withdrawal were utilized by the advancing Germans. The defence of the 54th Brigade was slowly outflanked by attacks from the north-east and north-west, the brigade fell back into Villeselve but were heavily bombarded by German Artillery from around 12:00. British troops, backed up by French infantry attempted to hold the line here but the French received orders to retreat, leaving the British flank exposed; the British retreated with the French and fell back through Berlancourt to Guiscard. The 54th Brigade ordered the retirement of what was left of their battalions to Crepigny and at 03:00 on the 25 March they slipped away under cover of darkness to Beaurains. Further north, the 1/1st Herts war diary read,

"After an intense bombardment of our trenches the enemy attacked with large numbers. The Bn, after heavy fighting, retired to a crest in front of the FEVILLERS-HEM WOOD ROAD. Here the Bn lost its Commanding Officer, Lieut. Colonel E.C.M. PHILLIPS, about whom, up to the time of writing, nothing is known. In the evening the Bn got orders to withdraw through the 35th Division to MARICOURT where the Bn spent the night.(24 March 1918)"

by nightfall, the British had lost the line of the Somme, except for a stretch between the Omignon and the Tortille. The fighting and retirements in the face of unceasing pressure by the German Second Army led the right of the Third Army to give up ground as it tried to keep contact with Fifth Army.

Day 4, 24 March
In the late evening of 24 March, after enduring unceasing shelling, Bapaume was evacuated and then occupied by German forces on the following day. The British official historian, Brigadier-General Sir James E. Edmonds wrote,

"The whole of the Third Army had swung back, pivoting on its left, so that, although the VI and XVII Corps were little behind their positions of the 21st March, the right of V Corps had retired seventeen miles [27 km]. The new line, consisting partly of old trenches and partly shallow ones dug by the men themselves, started at Curlu on the Somme and ran past places well known in the battle of the Somme, the Bazentins and High Wood, and then extended due north to Arras. It was, for the most part, continuous, but broken and irregular in the centre where some parts were in advance of others; and there were actually many gaps...Further, the men of the right and centre corps..were almost exhausted owing to hunger and prolonged lack of sleep.'"

After three days the infantry was exhausted and the advance bogged down, as it became increasingly difficult to move artillery and supplies forward to support them over Somme battlefield of 1916 and the wasteland of the 1917 German retreat to the Hindenburg Line. Advancing German troops had also fallen onto the abandoned British supply dumps which caused some demoralisation, when German troops found out that the Allies had plenty of food despite the U-boar campaign, with luxuries such as chocolate and even Champagne falling into their hands. Fresh British troops had been hurried into the region and were moved towards the vital rail centre of Amiens.

The German breakthrough had occurred just to the north of the boundary between the French and British armies. The new focus of the German attack came close to splitting the British and French armies. As the British were forced further west, the need for French reinforcements became increasingly urgent. In his diary entry for 24 March, Haig acknowledged important losses but derived comfort from the resilience of British rearguard actions,

"By night the Enemy had reached Le Transloy and Combles. North of Le Transloy our troops had hard fighting; the 31st, Guards, 3rd, 40th and 17th Divisions have all repulsed heavy attacks and held their ground.'"

Haig was seriously anxious about the numbers of French reserves and their commitment to the British predicament. Late that night Haig (after first dining with General Byng when he urged Third Army to "hold on ... at all costs") travelled to Dury to meet the French commander-in-chief, General Pétain, at 23:00. Pétain was increasingly convinced that the British Fifth Army was beaten and that the "main" German offensive was about to launched against French forces in Champagne. Pétain was under enormous pressure from his government to safeguard Paris, which was under long-range German artillery bombardment. On 24 March, he informed Haig that the French army was preparing to fall back towards Beauvais to protect Paris if the German advance continued. This would have created a massive gap between the British and French armies, and almost certainly forced the British to retreat towards the channel ports. Alarmed by Pétain’s pessimism the British commander-in-chief, Field Marshal Haig sent a telegram to the War Office to request an Allied conference.

Day 5, 25 March
The movements of 25 March were extremely confused and reports from different battalions and divisions are often contradictory. An unidentified officer's account of his demoralizing experiences that day is quoted in the British Official History:

"What remains in my memory of this day is the constant taking up of new positions, followed by constant orders to retire, terrible blocks on the roads, inability to find anyone anywhere; by exceeding good luck almost complete freedom from shelling, a complete absence of food of any kind except what could be picked up from abandoned dumps."

The weight of fighting developed to the north of the 54th Brigade, who were now fighting with the French and the battered remnants of the 18th Division who could scarcely raise enough men to form a small Brigade. By 10:00 on the 25th, the left flank of 7th Bedfordshires was again exposed as the French around them retreated, so another retirement was ordered. They withdrew back to Mont Du Grandu further south and away from the British Fifth Army. Midday saw them in a stronger position until the French artillery and machine guns opened fire on them, thinking they were Germans, forcing them to retire, yet again, to high ground west of Grandu.

The remaining troops of the 36th Division were ordered to withdraw and reorganize. In order to give support to French troops now holding the front, they set off on a 15 mi march west. Around midday, they halted for a few hours rest near Avricourt. While there they received orders to head for a new line which would be formed between Bouchoir and Guerbigny. During the day, the German Army picked up the pace of their advance and pressed forward at an alarming pace covering many miles. Allied troops and civilians with laden carts and wagons filled the roads streaming south and west. The Germans passed through Libermont, and over the Canal du Nord. Further north, the town of Nesle was captured, while to the south west of Libermont German troops soon faced the French along the Noyon-Roye road. The 1/1st Herts having spent the night in Maricourt, "marched from MARICOURT to INSAUNE. The march was continued after breakfast across the River SOMME at CAPPY to CHUIGNOLLES, where the Bn reorganised and spent the night.”(25 March 1918)

"More orders were received at 3pm to move to Varesnes on the south bank of the River Oise but whilst en-route they were countermanded with surprise orders to counter attack and retake a village called Babouef. Therefore, the war worn Brigade who had been fighting and marching for four punishing days solid were about faced and moved off to the attack with an enthusiasm that is nothing short of incredible. By rights, the Brigade should have been incapable of the action yet those quoted as being there remark that it was the most memorable event of the entire rearguard action. At 5pm, with the Fusiliers on the right, the Bedfords on the left and the Northamptons in reserve, the Brigade formed up with the Babouef to Compeigne road on their right and the southern edge of the woods above Babouef to their left. The Germans had not expected a British counter attack, thinking there was nothing but ragged French units in their area, so were surprised at the arrival of three small but determined British battalions. They put little fight up and many Germans fell in the hand to hand fighting that lasted for around 20 minutes before the village was secured and the remaining enemy – that could get away – fled. Ten machine guns and 230 German prisoners were taken with very light casualties recorded by the Brigade; an incredible feat whatever way you view it. They dug in on the German side of the village amongst the cornfields and settled in for the night. Cooking limbers were even brought up and the idea of a quiet night gave the exhausted men a welcomed break from the extreme stress they had all been through in the past five days. Unfortunately, their rest did not last long."

The Royal Flying Corps (RFC) flew sorties at low altitude in order to machine-gun and bomb ground targets and impede the German advance. On 25 March, they were particularly active west of Bapaume. Rearguard actions by the cavalry in the Third Army slowed the German advance but by 18:00 Byng had ordered a further retirement beyond the Ancre. Through the night of 25 March, the men of the Third Army attained their positions but in the process gaps appeared, the largest of over 4 mi between V and VI Corps. Sir Henry Wilson, the Chief of the Imperial General Staff, arrived at General Headquarters at 11:00 on 25 March, where they discussed in detail the delicate position of the British Armies astride the river Somme. Haig wanted at least 20 French divisions to help defend Amiens and delivered in person a message for the French Premier Clemenceau. The Doullens Conference took place the next day.

Day 6, 26 March
The Allied conference demanded by Haig took place on 26 March at Doullens. Ten senior Allied politicians and generals were present, including the French president, prime minister and Winston Churchill (the Minister of Munitions), Generals Pétain, Foch, Haig and Wilson (the Chief of the Imperial General Staff). The result of the meeting was that General Foch was first given command on the Western Front and then Generalissimo of all Allied forces everywhere. It was agreed to hold the Germans east of Amiens and an increasing number of French soldiers would come to the aid of Gough’s Fifth Army, eventually taking over large parts of the front south of Amiens.

Ludendorff issued new orders on 26 March. All three of his armies were given ambitious targets, which included the capture of Amiens and an advance towards Compiègne (close to Foch’s own head quarters). Neither of these objectives would be achieved, although Montdidier would fall on 27 March. Edmonds the Official Historian noted,

"On 26 March, the general direction of the two northern German Armies of attack, the Second and Seventeenth, was still due west; the Eighteenth Army opened fanwise, its northern boundary some six miles, south of the Somme at Peronne, running west, but its southern one near Chauny, pointing south-west.' In the north the 'Seventeenth Army...met with very determined resistance, but it was hoped, with the aid of the Second Army on the south, which had not encountered so much opposition, and of new attacks – 'Mars' and 'Valkyrie'...on the north [towards Arras] that the Seventeenth would be able to get going again.'"

A gap in the British line near Colincamps was held by newly arrived elements of the New Zealand Division that had moved to the line Hamel-Serre to close the gap. They were assisted by British "Whippet" tanks which were lighter and faster than the Mark IVs. This was their first time in action. At around 13:00, "twelve ‘whippet’ tanks of the 3rd Tank Battalion suddenly appeared from Colincamps, which they had reached at midday, and where there were only two infantry posts of the 51st Div. Debouching from the northern end of the village, they produced an instantaneous effect. Some three hundred of the enemy, about to enter it from the east, fled in panic. A number of others, finding their retreat cut off, surrendered to some infantry of the 51st Divn…" Despite this success German pressure on Byng's southern flank and communication misunderstandings resulted in the unfortunate and premature retirement of units from Bray and the abandonment of the Somme crossings westwards. To the south of the Somme the 1/1st Herts were:

"... moved forward through CHUIGNES to a line in front of the CHUIGNES-FOUCACOURT road I support to the 117th and 118th Bdes. After covering their retirement the Bn fought a series of rearguard actions on the many ridges in front of the village of CHUIGNOLLES. In the afternoon the Bn occupied the PROYART-FROISSY road. Orders were given for the Bn to withdraw behind PROYART, astride the FOUCACOURT-MANOTTE road.”26 March 1918"

26 March was also a bad day for French forces on the extreme right (south) of the line troops (now under the command of General Fayolle) fell back in the face of protracted fighting and serious gaps appeared between the retreating groups.

"Of the front between the Oise and the Somme, the French held 18 miles [29 km] and the British 19 miles [31 km]. It was for the greater part a continuous line; but there was a three-mile space between the French left at Roye and the right of the XIX Corps at Fransart... To fill the gap there were available the remains of the four divisions, the 20th, 36th, 30th and 61st, of the XVIII Corps. These General Maxse had instructed to assemble at and north-west of Roye, in order to keep connection between Robillot's Corps and the XIX Corps and to ensure that if the Allied Armies separated, the XVIII Corps might still remain with the Fifth Army.'"

Most of the Ulster Division had arrived in their new lines around 02:00 on 26 March, and were able to sleep around six hours, the longest continuous sleep they had in six days. While they slept, German troops entered and occupied Roye. Meanwhile, the 9th Irish Fusiliers were a long way behind the rest of the Division, delayed by their action north of Guiscard the night before. Their retreat was a 30 mi continuous night march from Guiscard to Erches, their designated position at the centre of the new line, along the Guerbigny–Bouchoir road. They route-marched through Bussy to Avricourt, then on to Tilloloy, Popincourt, Grivillers, Marquivillers, and finally via Guerbigny to Erches, where they arrived, completely exhausted, around 11:00 on 26 March. The German troops who took Roye during the early hours of the morning, continued to advance on the Bouchoir–Guerbigny line and by mid-morning were in Andechy, 3.5 mi from the new British line.

Day 7, 27 March
The town of Albert was relinquished during the night of 26/27 March,

"With the choice of holding the old position on the heights east of Albert, on the left bank of the Ancre, or the high ground west of the devastated town, it had been decided to adopt the latter course. The ruins of Albert were therefore abandoned to the enemy."

the town was then occupied by German troops who looted writing paper, wine and other items they found. 27 March saw a series of continuous complex actions and movements during the defensive battle of XIX Corps against incessant German attacks from the north, east and north-west around Rosières, less than 20 mi east of Amiens. This was a consequence of the precipitate abandonment of Bray and the winding line of the Somme river, with its important bridgeheads westwards towards Sailly-le-Sec, by the Third Army on the afternoon of 26 March. The important communications center of Montdidier was lost by the French on 27 March.

The 1/1st Herts war diary reads,

"The Bn who were in trenches on both sides of the road were ordered to move forward in support of the 118th Bde, being temporarily attached to the 4/5th Black Watch Regt. Soon after moving forward British troops were seen retiring to the left in large numbers. Consequently the Bn was ordered to move forward to the left and cover their withdrawal. After having skilfully carried this out the Bn conformed to the general withdrawal to a line between MORCOURT and the FOUCACOURT–LAMOTTE road. The Bn collected and assembled, then counter attacked the enemy, driving him back to within a few hundred yards of the village of MORCOURT.(27 March 1918)"

Day 8, 28 March
The focus of the German attack changed again on the 28th. This time, in an attempt to get the direction of the offensive back on track, it was the Third Army, around Arras, that would be the target of Operation Mars. Twenty nine divisions attacked Byng’s army, and were defeated in a day. In contrast, Ludendorff's troops, advancing from the original front at St. Quentin, had penetrated some 40 mi deep into British lines by this time, having reached Montdidier. The result was that General Rawlinson replaced General Gough on the 28th, despite the latter having organized a long and reasonably successful retreat given the conditions.

The northern part of the German attack against the Third Army was less successful than that against the Fifth Army. The German Seventeenth Army east of Arras only advanced 2 mi during the offensive, largely due to the British bastion of Vimy Ridge, the northern anchor of the British defences. Although Below made more progress further south of Arras, his troops posed less of a threat to the stronger Third Army than the Fifth Army, because the British defences to the north were superior and because of the obstacle of the old Somme battlefield. Ludendorff expected that his troops would advance 5 mi on the first day and capture the Allied field artillery, "We chop a hole. The rest follows." Ludendorff's dilemma was that the parts of the allied line that he needed to break most were also the best defended. Much of the German advance was achieved quickly but in the wrong direction, on the southern flank where the Fifth Army's defences were weakest. Operation Mars was hastily prepared to try to widen the breach in the Third Army lines but was repulsed, achieving little but German casualties.

The Herts war diary reads,

"The position gained was held stubbornly against all enemy attempts to retake it. On the morning of the 28th orders were received for a speedy evacuation of this line. The enemy at this point was well in our rear in possession of LAMOTTE so that the withdrawal had to be done quickly. The Bn showed the utmost resource during this dangerous manoeuvre, loosing [sic] very few men. The retirement took place in daylight through HARBONNIERS & CAIX. At the latter place the Bn attacked the enemy successfully but thereafter had orders to retire on COYEUX where it again assembled in a counter attack in which the acting Commanding Officer was wounded. During the day rearguard actions took place along the river bed to IGNAUCOURT. In the evening the Bn went into trenches in front of AUBERCOURT.(28 March 1918)"

Day 9, 29 March
The Herts war diary reads, The enemy remained fairly quiet except for machine gun fire. (29 March 1918)

Day 10, 30 March
The last general German attack came on the 30th. Von Hutier renewed his assault on the French on the south of the newly formed Somme salient, while von der Marwitz launched an attack towards Amiens (First battle of Villers-Bretonneux, 30 March – 5 April). Some British ground was lost but the German attack was rapidly losing strength. The Germans had suffered massive casualties during the battle, many to their best units and in some areas the advance slowed, when German troops looted Allied supply depots.

The Herts war diary reads:

"Today (March 30) saw the enemy advancing on the right flank on the other side of the river de LUCE. He very soon enfiladed our positions both with artillery and machine guns. This was followed by a strong enemy bombardment and attack on our front. After a stubborn resistance the Bn fell back to the BOIS DE HANGARD, making two counter attacks en route. (Comment: Lt John William CHURCH died from his wounds and Lt Angier Percy HURD was killed on 30-3-18).(30 March 1918)"

Day 14, 4 April
The final German attack was launched towards Amiens. It came on 4 April, when fifteen divisions attacked seven Allied divisions on a line east of Amiens and north of Albert (towards the Avre River). Ludendorff decided to attack the outermost eastern defenses of Amiens centred on the town of Villers-Bretonneux. His aim was to secure that town and the surrounding high ground from which artillery bombardments could systematically destroy Amiens and render it useless to the Allies. The fighting was remarkable on two counts: the first use of tanks simultaneously by both sides in the war and a night counterattack hastily organized by the Australian and British units (including the exhausted 54th Brigade) which re-captured Villers-Bretonneux and halted the German onslaught. From north to south, the line was held by British and Commonwealth troops, specifically the 14th Division, 35th Australian Battalion and 18th Division. By 4 April the 14th Division fell back under attack from the German 228th Division. The Australians repulsed the 9th Bavarian Reserve Division and the British 18th Division held off the German Guards Ersatz Division and 19th Divisions (the First Battle of Villers-Bretonneux).

Day 15, 5 April
An attempt by the Germans to renew the offensive on 5 April failed and by early morning British Empire troops had forced the enemy out of all but the south-eastern corner of the town. German progress towards Amiens, having reached its furthest point westward had been held. Ludendorff called a halt to the offensive.

Analysis
The Germans had captured 1200 sqmi of France and advanced up to 40 mi but they had not achieved any of their strategic objectives. Over 75,000 British soldiers had been taken prisoner and 1,300 artillery pieces and 200 tanks were lost. It was of little military value with the casualties suffered by the German elite troops and the failure to capture Amiens and Arras. The captured ground was hard to move over and difficult to defend, as much of it was of the shell-torn wilderness left by the 1916 Battle of the Somme. Elsewhere the transport infrastructure had been demolished and wells poisoned during the German retreat to the Hindenburg Line in March 1917. The initial German jubilation at the successful opening of the offensive soon turned to disappointment as it became clear that the attack had not been decisive. Marix Evans wrote in 2002, that the magnitude of the Allied defeat was not decisive, because American reinforcements were arriving in large numbers, that by 6 April the BEF would have received 1,915 new guns, British machine-gun production was 10,000 per month and tank output 100 per month. The appointment of Foch as Generalissimo had created more unity of command in the Allied forces.

Casualties
In the British Official History (1935) Davies, Edmonds and Maxwell-Hyslop wrote that the Allies lost c. 255,000 men of which the British suffered 177,739 killed, wounded and missing, 90,882 of in the Fifth Army and 78,860 in the Third Army, of whom c. 15,000 died, many with no known grave. The greatest losses were to 36th (Ulster) Division,7,310, the 16th (Irish) Division, 7,149 and 66th (2nd East Lancashire) Division, 7,023 casualties. All three formations were destroyed and had to be taken out of the order of battle to be rebuilt. Six divisions each lost more than 5,000 men. German losses were 250,000 men, many of them irreplaceable élite troops. German casualties, from 21 March – 30 April. which includes the Battle of the Lys are given as 348,300. A comparable Allied figure over this longer period, is French: 92,004 and British: 236,300, atotal of c. 328,000. In 1978 Middlebrook wrote that casualties in the 31 German divisions engaged on 21 March were c. 39,929 men and that British casualties were c. 38,512. Middlebrook also recorded c. 160,000 British casualties up to 5 April, 22,000 killed, 75,000 prisoners and 65,000 wounded; French casualties were c. 80,000 and German casualties were c. 250,000 men. In 2002 Marix Evans recorded 239,00 men, many of whom were irreplaceable Stoßtruppen; 177,739 British casualties of whom 77,000 had been taken prisoner, 77 American casualties and the French lost 77,000 men, 17,000 of whom were captured. The Allies also lost 1,300 guns, 2,000 machine-guns and 200 tanks. In 2006 Zabecki gave 239,800 German, 177,739 British and 77,000 French casualties.