In the year AD
- The ninth and final crusade comes to an end as Saracen Turks led by Mamluk sultan of Egypt Khalil capture and sack Acre, the last and most important Crusader stronghold in the Holy Land, destroying the Latin Kingdom of Jerusalem and effectively shattering Crusader power in the region.
- Three independent mountain communities, Unterwalden, Schwyz, and Uri, unite against Hapsburg encroachment as the League of Forest Cantons, forming the nucleus of what will become the independent nation of Switzerland.
- Scottish nobles grudgingly recognize the authority of English king Edward I in exchange for his mediation of the succession crisis created by the death of Scottish king Alexander III in 1286.
- Pope Nicholas IV issues a papal bull confirming the independence of San Marino.
- Castilian king Sancho IV reconquers Tarifa from the Moors.
- The glassmakers of Venice are forced to move to the island of Murano in order to contain the risk of fire, establishing the a famous glass industry that would one day supply most of Europe's mirrors and chandeliers.
- The artificial Kunming Lake, later to become the site of the Qing Summer Palace, is constructed to the north of Beijing as a reservoir by famous engineer and astronomer Guo Shoujing.
- Japanese emperor Kameyama establishes the great Buddhist temple of Nanzenji in Kyoto.
- Dante pens a poem, later collected in La Vita Nuova, in which he first mentions Beatrice, the great love of his life.
These people were born in 1291:
These people died in 1291:
1290 - 1291 - 1292