Prussians settled in exile in Serbia stage a famous uprising.
1288 – 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.
1288 – 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.