1266

Events 
 Europe 
 February 26 – In the Battle of Benevento, an army led by Charles, Count of Anjou, defeats a combined German and Sicilian force led by King Manfred of Sicily. Manfred is killed in the battle and Pope Clement IV invests Charles as king of Sicily and Naples.
 July – Mary de Ferrers ordered to surrender land and Liverpool Castle to Edmund, second son of Henry III.
 October – In England, the Second Barons' War winds down as supporters of the slain rebel leader Simon de Montfort make an offer of peace to the king in the Dictum of Kenilworth; after slight modifications to the peace settlement, it is agreed to the following year.
 The war between Scotland and Norway ends as King Alexander III of Scotland and King Magnus VI of Norway agree to the Treaty of Perth, which cedes the Western Isles and Isle of Man to Scotland in exchange for a large monetary payment.
 In France, the gold écu and silver grosh coins are minted for the first time.

 Asia 
 Niccolo and Maffeo Polo, brother and uncle of Marco Polo reach Kublai Khan's capital Khanbaliq (now Beijing) in China, setting the stage for Marco's famous expedition starting five years later. Kublai Khan sends the Polos back with a message requesting the pope dispatch western scholars to teach in the Mongol Empire; however, this request is largely ignored.
 The Mamluk sultan Baibars expands his domain, capturing the city of Byblos (in present-day Lebanon) and the important castle of Toron from crusader states, and defeating the Armenians at Cilicia.

 Births 
 Hethum II of Armenia (died 1307)
 Beatrice Portinari, Dante Alighieri's beloved and guide through Heaven in The Divine Comedy (died 1290)

 Deaths 
 February 26 – King Manfred of Sicily
 October 21 – Birger jarl, Swedish regent and founder of Stockholm (born about 1210)
 Berke, khan of the Golden Horde
 Hugh Bigod, Justiciar of England
 Ariq Boke, regent of the Mongol Empire
 Eudes of Burgundy, Count of Nevers (born 1230)
 John of Ibelin, jurist of the Kingdom of Jerusalem (born 1215)
 Duke Świętopełk II of Pomerania
 Marie de Saint-Clair, grand master of the Priory of Sion
 May 7 — Farid-ud-din Ganj Shakar