Battle of Saint-Omer

The battle of Saint-Omer was a large action fought in 1340 as part of King Edward III's summer campaign against France launched from Flanders in the early stages of the Hundred Years' War. The campaign was launched in the aftermath of the battle of Sluys but proved far less successful for the English than this previous action and resulted in little change of situation for either side. The battle of Saint-Omer was the culmination of the northern fork of Edward's campaign and resulted in a tactical stalemate but forced a strategic withdrawal for the Anglo-Flemish forces.

The French border in 1340
By 1340, Flanders had been a reluctant part of France for centuries and frequent uprisings and wars of independence between the two nations had studded the Middle Ages. In the late 1330s, Flanders again struck out for self-determination, the French ruler Louis I of Flanders being overthrown in a bloody coup and replaced with the dictator Jacob van Artevelde. Edward III, seeking allies for his war against France, made an alliance with Artevelde and promised to fund his government and supply the wool vital for the Flemish economy provided the Flemish supported his operations and allowed Flanders to be used as a staging point for an invasion of France.

Artevelde agreed, but was secretly unwilling to commit all his resources to this war and also was not fully in control of the mercantile city states which emerged in the semi-independent region. Thus when Edward demanded 150,000 Flemish troops to be awaiting his arrival in 1340, he was somewhat surprised to discover on arrival that barely a fraction of this number had gathered. On Edward's passage he had won the great naval victory at Sluys and buoyed by this success determined to press his advantage on land too. He ordered Robert III of Artois, an old pretender to the title of Count of Artois to take 1,000 English and over 10,000 Flemish troops which had gathered into the Artois region and conduct a miniature chevauchée in the region, attempting to provoke the French into action and perhaps to capture an important fortified town such as Saint-Omer. Meanwhile, Edward would remain in Flanders and attempt to raise a second force which he would use to march on the border fortress of Tournai and lay siege to it.

The French were well aware of Edward's preparations and targets and so began their own campaign of strengthening their forts and positions in the region, as well as conducting a levee in Northern France to gather an army together for service against the Anglo-Flemish alliance. By July, King Philip VI had 25,000 men gathered to him in the region, many of them set up in well-prepared defensive positions, including Saint-Omer and Tournai.

Robert's campaign
Saint-Omer especially was given special attention by the French commanders as Robert failed to make the slightest precaution to conceal his destination, conducting a campaign of destruction almost in a direct line towards the French town. As he did so, Philip dispatched a force of approximately a thousand men to Saint-Omer under Eudes IV, Duke of Burgundy and then followed this a week later with another sizeable force under Jean I, Count of Armagnac. These men soon put the town onto a war footing, evacuating much of the non-military population, demolishing the suburbs and fortifying the town walls. Contrary to the beliefs and claims of Robert of Artois, there were no pro-Flemish supporters in the town and Robert's plan of simply marching up to the gates and being admitted was thus impossible and foolhardy. Nevertheless, he continued to close on the town and on the 25 July razed the neighbouring town of Arques to the ground before spreading out across the eastern fringes of Saint-Omer prior to attack.

Behind Robert, the lumbering French army of Philip VI was making slow progress towards his position and it became immediately obvious to the Anglo-Flemish commanders that there was no time for a siege and that in just a few days their army would be crushed between the French Royal army and the garrison of Saint-Omer. Aware that he might be forced to withdraw, Robert drew his forces up in front of Saint-Omer offering the garrison the chance of battle. Robert's dispositions put his best troops, the English longbowmen and men from Bruges and Ypres, in the centre, with the left wing made up of men from Ypres, Veurne and Mons and the right with further soldiers of Bruges. Behind this force was a large mixed force of men from across Flanders and the allied army's camp.

The battle
Burgundy and Armagnac were aware of the advance of Philip VI and resolved to await his arrival without giving battle. This plan came to nothing when a number of French knights, eager to engage with the enemy and disdainful of orders from their commanders urging restraint charged from the town and into the left wing of the allies. They were beaten back from the barricades but as they retreated, the Ypres infantry followed them into the open ground in front of the position. Seeing this, the French force turned and charged the Flemings again, creating a melee which lasted throughout the afternoon. From the walls Burgundy and Armagnac saw the advantage of the gap in the allied line and each rode out of the town with over 400 of the best cavalry available to attack the flanks of the allied army.

Armagnac struck the already weakened left flank, and rapidly smashed a hole in the weakened levies holding the position. Rapidly routing the defenders, Armagnac's men poured into the allied encampment and routed the disorganised reserve too, killing thousands of soldiers as they fled and looting the baggage and supplies. Their undisciplined rampage in the rear of the allied army was highly destructive but also highly wasteful, as had they been able to retain cohesion then they could have fallen on the rear of the right wing and annihilated Robert's army. As it was, the English and Bruges troops on the centre and right positions were far more successful, meeting Burgundy's charge with discipline and a hail of arrows.

Unaware of the carnage behind them they surrounded Burgundy's cavalry and overwhelmed them by weight of numbers, pushing them back towards the town and engaging in a furious brawl in the streets of the undemolished northern suburbs. A fierce rearguard action by French townsmen and archers was all that prevented Robert's men from breaking into the town and it was some time before the gates could be finally forced shut behind the remnants of Burgundy's force. Nobody in the town or Robert's army was aware that a mile behind them the French held the field. As darkness fell, Robert and Armagnac trooped back to their respective positions on the same road resulting in a number of frantic skirmishes in the dark but little significant fighting.

Aftermath
When the morning came the full extent of the disaster which had befallen his reserve became apparent to Robert. Having failed to capture the town or defeat the French force in open battle, he knew there was no choice but to abandon the campaign before Philip's superior army cut him off from Flanders. Abandoning all that could not be rapidly carried, Robert returned to Edward's army, having kept his best units intact and claiming at least a partial victory. On the field behind him he had left over 8,000 Flemish soldiers killed, a casualty list several times that of the French who lost only a handful. The very high figure was caused primarily by the rout of the untrained Flemish reserves at the rear of the battleline. The battle had few long-lasting consequences as the main forces of both sides were still battle worthy and the strategic situation remained unchanged. There were three short term significant effects however; morale amongst the Flemish portions in Edward's army collapsed, causing great problems within his force which would eventually shake apart over arguments over payment and confidence in its general. Secondly, Southern Flanders was now undefended as the men intended for this purpose were now dead outside Saint-Omer and thus French cavalry were free to conduct raids into the area and create havoc in the rear of Edward's forces causing further morale and supply problems. Thirdly, the towns which had suffered especially badly such as Ypres, Bruges and some elements of the burgers of Ghent made peace overtures towards Philip, undermining English support in major Flemish centres or supply and recruitment. Edward was undeterred by any of this in his aim of invading Northern France and shortly afterwards departed his positions at Ghent and marched to unsuccessfully besiege Tournai.