In March 1426, English forces led by John, Duke of Bedford, defeated a Franco-Breton army at the Battle of St. James near Avranches in Normandy. The victory forced Duke John V of Brittany to recognize English suzerainty temporarily, consolidating Lancastrian holdings in France. It exemplified the ongoing guerrilla and siege warfare of the Hundred Years' War, with shifting alliances testing the limits of feudal loyalties.

Such border skirmishes inspired Breton and French oral traditions and ballads celebrating resistance or lamenting defeats, preserving unvoiced regional narratives. English court poets used these military successes to bolster propaganda in verse, while the instability fueled reflective poetry on loyalty and fortune. These events contributed to a rich tapestry of war poetry that later informed Renaissance explorations of chivalry and national identity.