Battle of the Hills

The Battle of the Hills (Bataille des Monts) also known as the Battle of the Hills of Champagne and the Third Battle of Champagne, was a battle of the First World War that was conducted during April and July 1917. The offensive was intended to be an auxiliary attack to that of the Groupe d'armées du Nord (GAN) along the Chemi des Dames in the Second Battle of the Aisne. General Anthoine, commander of the Fourth Army had originally planned a supporting attack but this was rejected by Nivelle who required a more ambitious effort. Anthoine replaced his draft plan with a proposal for a frontal attack by two corps on an 11 km front, intended to break through the German defences on the first day and commence exploitation the following day. The battle took place east of Rheims, between Prunay and Aubérive, in the province of Champagne, along the Moronvilliers Hills. Despite German counterattacks on the 19 and 23 April, the French 4th Army improved its positions by advancing slightly on the heights of Moronvilliers.

Background
The German defences between Suippes and the Vesle lay on a plateau overlooked by Mont Berru 267 m and along Moronvilliers Ridge, about 10 km long and about 210 m high, dominating the plain of Chalons and a parallel lower ridge about 130 m high, which met the main ridge at the village of Beine. The two ridges declined steeply to the south. The German defence was based on positions 9 – deep. The first position lay at the foot of the forward slope with three trench lines, the second position was on the reverse slopes connected by tunnels, the third position had been built on the north slope of the second ridge and the fourth position lay along the foot of the reverse slope. A fifth reserve position Suippestellung lay further back. The Third Army positions were divided into five sectors, from Béthény to Prosnes, Prosnes to Sainte-Marie-à-Py, Sainte-Marie-à-Py to Tahure, Tahure to Rouvroy and Rouvroy to Argonne, with 17 divisions, including Eingreif divisions and fresh units transferred from other parts of the Western Front.

The French Fourth Army had the VIII, XVII and XII corps on an 18 km front between Ferme Marquises and Massiges, with 1,600 guns. The French front line was just north of the Reims, St. Hilaire le Grand, St. Ménéhould, Verdun road and about 400 ft below the peak of Mont Haut. To reach the summit the French infantry would have to advance for about 2 mi up a series of steep rises. Tank Groupement III commanded by Captain H. Lefebvre, had two Schneider CA1 groups, Artillerie Spéciale (AS) 1 and AS 10 of eight tanks each, reinforced by some Saint-Chamond tanks. The Aéronautique Militaire on the Fourth Army front had 22 Escadrilles (Squadrons) of aircraft and eleven balloon companies.

German defensive preparations
The two defensive lines built before the Herbstschlacht (Second Battle of Champagne) of September – November 1915 had been increased to four lines and in places to five lines, which enclosed defensive zones by early 1917. The number of communication trenches in the defensive zones had been increased, trenches and dug-outs deepened and huge amounts of concrete used to reinforce the fortifications against French artillery-fire. Two tunnels capable of accommodating several battalions of infantry had been dug under the north slope of Mont Cornillet and the north-east side of Mont Perthois. The Cornillet tunnel had three galleries with Décauville (light) railways along two of the galleries, with a transverse connecting tunnel and air shafts dug up to the top of the hill. The tunnel under Mont Perthois was less elaborate but had many machine-gun posts and exits from which a French attack on Le Casque and Le Téton could be engaged and counter-attacked.

Battle
On 17 April the Fourth Army on the left of Groupe d'armées de Centre (GAC) began the subsidiary attack in Champagne from Aubérive to the east of Reims which became known as Bataille des Monts, with the VIII, XVII and XII Corps on an 11 km front. The attack began at 4:45 a.m. in cold rain alternating with snow showers and pitch black rather than dawn light. Aeroplanes and observation balloons were grounded by high gusty windsThe right flank guard to the east of Suippes was established by the 24th Division and Aubérive on the east bank of the river and the 34th Division took Mont Cornillet and Mont Blond. The "Monts" were held against a German counter-attack on 19 April by the 5th, 6th (Eingreif divisions) and the 23rd division and one regiment between Nauroy and Moronvilliers. On the west bank the Moroccan Division was repulsed on the right and captured Mont sans Nom on the left. To the north-east of the hill the advance reached a depth of 1.5 mi and next day the advance was pressed beyond Mont Haut. The Fourth Army attacks took 3,550 prisoners and 27 guns. German attacks on 27 May had temporary success before French counter-attacks recaptured the ground around Mont Haut; lack of troops had forced the Germans into piecemeal attacks instead of a simultaneous attack along all of the front.

Analysis
In the attack of 17 April, the Fourth Army had swiftly reached the crest of the Moronvilliers massif but German observation over the battlefield had enabled acccurate German artillery-fire against the French infantry, making the attack costly, although fog had protected the French infantry from the fire of some German machine-guns. Tunnels driven through the chalk connected the foremost German positions with the rear and German infantry could fire until the last moment, before retiring through them to the northern slopes, although the French heavy artillery had blocked some tunnels, subways, deep dugouts and caverns, in which some German troops were entombed and others were overrun and captured. As the French infantry encountered the German reverse-slope defences, fatigue, losses and the relatively undamaged state of the German positions stopped the French advance. Possession of the crest was a substantial tactical advantage to the French, which denied the Germans observation to the south but the observation posts established on the heights were highly vulnerable to German bombardment and surprise attacks, against which the French had to keep large numbers of infantry close to the front, ready to intervene but vulnerable to German artillery-fire. Ludendorff called the loss of the heights a "severe blow" and sixteen German counter-attacks were made against the French positions along the heights in the next ten days, with little success.