The second division, of French and Breton men-at-arms, attacked but their charge was halted when they fell into a camouflaged ditch in front of the English position.

Northampton was concerned that the English archers were running out of arrows and that the ditch was so full of dead and wounded men and horses as to be ineffective as an obstacle.

[7][8][9] Starting in early June 1341 John seized almost all of the fortified places in Brittany and by mid-August had all but made good his claim to the Duchy.

Philip found the idea of having a relative as the duke attractive as it would bring the traditionally semi-autonomous province more firmly under royal control.

This was a small but strongly walled town with access to the sea and from there Joanna retained control of most of western Brittany, setting up her son as the faction's figurehead and heir to his father's claim to the duchy.

She despatched her senior counsellor, Amaury of Clisson, to Edward III in England with a large sum in cash to encourage English military intervention and waited on events.

By July Joanna had been forced back to the far west of Brittany and was besieged in the port of Brest, the only remaining fortified place held by her faction.

[24] Charles of Blois and a large army had invested the town[25] and fourteen mercenary galleys, hired from Genoa, blockaded it from the sea.

Charles promptly broke off the siege and withdrew, abandoning western Brittany, where the populace strongly favoured the Montfort cause.

Edward III was planning to follow on with a substantial force and so Northampton's first mission was to secure a port on the north coast of Brittany.

Edward's contingent was still in England waiting for shipping to be assembled and the French mistakenly believed it would be used in northern France, probably disembarking in Picardy.

They were joined by the survivors of the 234-strong advance party which had arrived three months earlier – of whom 34 were men-at-arms and 200 archers – and at least one other group of English troops of 110 men.

[43] Matthew Bennett has suggested "perhaps 3,000 men-at-arms and 1,500 Genoese mercenaries" as Charles' total force, which he opines was considerably more men than in the English army; a little later he also mentions lightly armoured Breton infantry leading the French attack.

[46][47][48][49][50] They were mounted on entirely unarmoured horses and carried wooden lances, usually ash, tipped with iron and approximately 4 metres (13 ft) long.

[note 3] Computer analysis by Warsaw University of Technology in 2017 demonstrated that heavy bodkin point arrows could penetrate typical plate armour of the time at 225 metres (738 ft).

Regular resupply of ammunition would be required from the wagons to the rear; the archers would also venture forward during pauses in the fighting to retrieve arrows.

[44][note 5] A trained crossbowman could shoot his weapon approximately twice a minute[64] to a shorter effective range than a longbowman[65] of about 200 metres (660 ft).

[66] Charles, now more accurately informed about the size of Northampton's force, decided to relieve Morlaix and his army marched back to the west.

The large village of Lanmeur was 11 kilometres (7 mi) north east of Morlaix and a little before reaching it the English found a suitable defensive position and dug in.

[44][67] A wood 100 metres (330 ft) behind them was too dense for cavalry to penetrate readily and so positioned their baggage train there – it would act as a rallying point if the battle went against them.

[67] Charles of Blois' army was advancing west along the coast road and it is possible his cavalry spent the night in the village of Lanmeur with the infantry bivouacked further east.

Once the English position just to the south west was identified on the morning of 30 September Charles spent some time organising his army into battle formation.

Several accounts state that the foremost division consisted largely of Breton levy infantry, the need to pass them through the cavalry in the village explains why the French did not start their attack until about 3:00 pm.

The majority state that it was made up of Breton levy infantry,[73][45][44] but Sumption writes that it was predominately Franco-Breton mounted men-at-arms,[40] and DeVries that it was a mix.

The English archers plied a deliberately aimed hail of arrows into this large, stationary, close-range target to great effect.

This may be attributable to the chivalric ideals held by knights of the time: nobles may have preferred to die in battle, rather than dishonourably decline to fight, especially against an outnumbered enemy.

[76] Northampton was concerned that the English archers were running low on arrows and that the ditch was less of an obstacle, both because it was no longer a surprise and because it was bridged in many places by the dead and wounded bodies of men and horses.

[83][84] The garrison of Morlaix held out and when Edward III arrived at Brest on 26 October the siege was abandoned and Northampton marched to join him.

He campaigned with Edward III in 1359–1360 and was one of the negotiators of the Treaty of Brétigny in 1360 which ended the Edwardian phase of the war with a stunning English victory.

[91] It was the first major land battle of the Hundred Years' War[33][45][92] and the first time the English tactic of deploying their men-at-arms on foot with massed longbowmen on either flank was seen outside Britain.