Lord Edward's Crusade, sometimes called the Ninth Crusade, was a military expedition to the Holy Land under the command of Edward, Duke of Gascony in 1271–1272. It was an extension of the Eighth Crusade and was the last of the Crusades to reach the Holy Land before the fall of Acre in 1291 brought an end to the permanent crusader presence there.

The siege of Acre took place in 1291 and resulted in the Crusaders' losing control of Acre to the Mamluks. It is considered one of the most important battles of the period. Although the crusading movement continued for several more centuries, the capture of the city marked the end of further crusades to the Levant. When Acre fell, the Crusaders lost their last major stronghold of the Crusader Kingdom of Jerusalem. They still maintained a fortress at the northern city of Tartus, engaged in some coastal raids, and attempted an incursion from the tiny island of Ruad; but, when they lost that, too, in a siege in 1302, the Crusaders no longer controlled any part of the Holy Land.