|Centuries:||12th century – 13th century – 14th century|
|Decades:||1250s 1260s 1270s – 1280s – 1290s 1300s 1310s|
|Years:||1285 1286 1287 – 1288 – 1289 1290 1291|
- June 5 – John I of Brabant defeats the duchy of Guelders in the Battle of Worringen — one of the largest battles in Europe of the Middle Ages — thus winning possession of the duchy of Limburg. The battle also liberates the city of Cologne from rule by the Archbishopric of Cologne; it had previously been one of the major ecclesiastical principalities of the Holy Roman Empire.
- August 8 – Pope Nicholas IV proclaims a crusade against King Ladislaus IV of Hungary, who had lost credibility by favoring his semi-pagan Cuman subjects and in general refusing to conform to the social standards of western Europe.
- The Scots Parliament creates a law allowing women to propose marriage to men during leap years; men who refuse such proposals are required to pay a fine to the spurned bride-to-be.
- The oldest surviving bell in the clocks atop the dome of St. Peter's Basilica in Rome dates to 1288.
- Vietnamese general Tran Hung Dao sinks the entire fleet of an invading Yuan dynasty Mongol army by placing steel-tipped bamboo stakes in the Bach Dang River, near Halong Bay.
- The Japanese era Koan ends, and the Shōō era begins.