War and politics
- King Charles II of Naples is captured in a naval battle off Naples by Roger of Lauria, admiral to King Peter III of Aragon.
- The Statute of Rhuddlan is created, formally incorporating Wales into England in the entity England and Wales.
- Battle of Meloria: The Italian city-state of Genoa defeats its rival Pisa, ending Pisa's marine power and hastening the city's decline in power.
- King Stefan Dragutin of Serbia receives Belgrade, Syrmia, and other territories from Hungary, when his son marries the king of Hungary's cousin.
- Mamluk sultan of Egypt Qalawun signs a 10-year truce with the Crusader city of Acre; he will violate the truce on pretexts in 1290.
- The Mongol Golden Horde, led by Nogai Khan, attacks Hungary a second time.
- The Kingdom of Germany imposes a trade embargo on Norway, due to the latter pillaging a German ship. The embargo cuts off vital supplies of grain, flour, vegetables and beer, causing a general famine.
- The infamous parallel port