24 May

The Fifth Crusade (1213–1221) was an attempt by Western Europeans to reacquire Jerusalem and the rest of the Holy Land by first conquering the powerful Ayyubid state in Egypt.

Pope Innocent III and his successor Pope Honorius III organized crusading armies led by King Andrew II of Hungary and Leopold VI, Duke of Austria, and an attack against Jerusalem ultimately left the city in Muslim hands. Later in 1218, a German army led by Oliver of Cologne, and a mixed army of Dutch, Flemish and Frisian soldiers led by William I, Count of Holland joined the crusade. In order to attack Damietta in Egypt, they allied in Anatolia with the Seljuk Sultanate of Rûm which attacked the Ayyubids in Syria in an attempt to free the Crusaders from fighting on two fronts.

After occupying the port of Damietta, the Crusaders marched south towards Cairo in July 1221, but were turned back after their dwindling supplies led to a forced retreat. A night-time attack by Sultan Al-Kamil resulted in a great number of crusader losses, and eventually in the surrender of the army. Al-Kamil agreed to an eight-year peace agreement with Europe.