Siege of Brest (1342)

The siege of Brest took place in 1342 during the Breton Civil War. When the Duke of Brittany died childless in 1341 the title was contested by Charles of Blois and John of Montfort. Charles was the nephew of the French king, Philip VI (r. 1328–1350), who supported him with a large army. Charles invaded Brittany, making good progress and taking John prisoner. John's wife, Joanna of Flanders, took up the Montfortist cause and fought on. As France and England had been fighting the Hundred Years' War since 1337 Joanna appealed to Edward III, the English king, for military assistance, which was promised.

It was slow in coming and the Montfortist forces were pushed back across Brittany. By July 1342 Joanna was besieged in Brest, the last Breton fortification held for the Montfort cause, by Charles and a large army. The town was blockaded from the sea by 14 mercenary Genoese galleys. On 18 August an English fleet of 260 ships, commanded by William of Northampton, sailed into the Brest Roads and overwhelmed the galleys, burning 11. The English ships carried only 1,350 fighting men, a force far smaller than that of the French army. But seeing so many English ships crowded into the Brest Roads and the English vanguard disembarking onto the beach, the French anticipated an attack by a vast host. Charles promptly broke off the siege and withdrew, abandoning western Brittany. The historian Jonathan Sumption describes this reaction as extraordinary. The English were reinforced over the next two months and held Brest until 1362. The Breton Civil War continued until 1365, the Hundred Years' War until 1453.