It was garrisoned by 1,000–1,500 soldiers, who were supplemented by an unknown, large number of armed townsmen, and commanded by Raoul, the Count of Eu, the Grand Constable of France.

There was a further week's delay while the King and his council debated what to do, by which time it proved impossible to take any action with the main English army before winter.

[16] John, Duke of Normandy, the son and heir of Philip VI, was placed in charge of all French forces in south west France, as he had been the previous autumn.

[22] This reliance was misplaced given the naval technology of the time and the French were unable to prevent Edward III successfully crossing the Channel.

[22] The campaign began on 11 July 1346 when Edward's fleet of more than 700 vessels,[23] the largest ever assembled by the English to that date,[24] departed the south of England and landed the next day at St. Vaast la Hogue,[25] 20 miles (32 kilometres) from Cherbourg.

The English fleet paralleled the army's route, devastating the country for up to 5 miles (8 kilometres) inland and taking vast amounts of loot; many ships deserted, their crews having filled their holds.

[27] Caen, the cultural, political, religious and financial centre of north west Normandy, was Edward's initial target; he hoped to recoup his expenditure on the expedition and put pressure on the French government by taking this important city and destroying it.

[32] The new part of the city, the Ile Saint-Jean, was a wealthy district of merchants and landowners who lived on the island formed between the Orne and the Odon.

[29] The English army arrived outside the walls early on 26 July and immediately seized the undefended abbeys, before forming up for a planned attack on the old town.

Raoul of Eu had originally planned to defend the old town and the castle, but pressure from wealthy citizens persuaded him to shift the defence to the Ile Saint-Jean once the English had arrived.

This hasty withdrawal proved disastrous, as important precautions, vital for the area's defence, were overlooked in the hurried relocation of the defenders.

A small force was dispatched to blockade the castle in the north of the town, which was garrisoned by 300 soldiers under the command of Guillaume Bertrand, Bishop of Bayeux.

As they manoeuvred into position, the English archers and men-at-arms, eager for plunder, pre-empted his orders and rushed the bridges before the assault force was fully in place.

The river was low after a period of dry weather and English longbowmen and Welsh spearmen waded across, harassed by crossbow fire, and stormed the improvised defences along the riverbank.

The common soldiers among the fleeing French were cut down, as was normal at the time;[35] only a handful of the wealthier combatants and townsfolk were taken prisoner, among whom was the Count of Eu.

[37] The sack of the city continued for five days, during which Edward attempted and failed to capture the castle, and paid homage at the grave of his ancestor William the Conqueror, who was buried in the town.

[44] On 28 August the main French army under Philip VI was crushingly defeated at the Battle of Crécy with heavy loss of life.

[45][46] Edward III ended the campaign by laying siege to Calais, which fell after twelve months, securing an English entrepôt into northern France which was held for two hundred years.