1288

1288 was a leap year that began on Thursday and ended on Friday.

Millennium:	2nd millennium
Centuries:	12th century – 13th century – 14th century
Decades:	1250s  1260s  1270s  – 1280s –  1290s  1300s  1310s
Years:	1285 1286 1287 – 1288 – 1289 1290 1291

Events

• 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.