Fall of Acre
The Mamluk sultan al-Ashraf Khalil captured Acre, the last crusader stronghold, ending the crusader states in the Levant.

Dominique Papety · Public domain · Source
Beginning under Baybars, the Mamluks took the crusader castles one by one, destroying Antioch (1268) and Tripoli (1289). In April 1291 al-Ashraf Khalil surrounded Acre with a great army and siege engines, and the city fell six weeks later, on 18 May.
The Templars held their seaside fortress for ten days more. Tyre, Sidon and Beirut were soon abandoned and the Franks withdrew to Cyprus. Some two hundred years of crusading in the Holy Land had effectively come to an end.