On May 20, 1217, during the First Barons' War, the forces of the young English king Henry III, led by William Marshal, defeated the army of Prince Louis of France at the Second Battle of Lincoln. This victory was a turning point in the war, effectively ending Louis's claim to the English throne and securing the Plantagenet dynasty. The battle was followed by the Treaty of Lambeth in September, which formally ended the conflict and forced Louis to renounce his claims.

The battle was celebrated in contemporary chronicles and poems as a miraculous victory that saved England from French domination. The figure of William Marshal, who led the royal forces, became a legendary hero in later medieval literature, embodying the ideals of chivalry and loyalty. His life and deeds were commemorated in the History of William Marshal, a verse biography that stands as one of the most important works of medieval English literature.