Siege of Acre: Mamluk forces under the command of Sultan Al-Ashraf Khalil arrive at Acre to begin their siege of this, the last Christian Crusading outpost in the Holy Land. They will succeed in capturing Acre in a little over a month, bringing to an end the era of the Crusades and all the European Christian holdings in this region of the world.
Sultan Khalil leads a force of 160,000 infantry and 60,000 cavalry against just 17,000 infantry and 1,100 cavalry among the Christian defenders. Acre's defenses are strong, with two sets of walls twelve tall towers, but they are no match for the massive Muslim army with its huge catapults and other siege engines.
The power of Christian holdings in the Holy Land has been declining for several decades. One reason is that the Mamluks are far stronger than previous enemies; a second important reason is that the Crusaders have received little help and few reinforcements from Europe. This is mostly because popes have misused the Crusades has so much that they have debased the very idea of Crusading. Now no one is interested in heeding the repeated calls from the popes.