1266

By place

Europe

• February 26 - Battle of Benevento: The army of 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.
• June 23 - War of Saint Sabas: In the Battle of Trapani, the Venetians defeat a larger Genoese fleet, capturing all its ships.
• July - Mary de Ferrers is 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 4000 merks.

  Asia

• Niccolo and Maffeo Polo, father and uncle of Marco Polo, reach Kublai Khan's capital Khanbaliq in China, setting the stage for Marco's famous expedition 5 years later. Kublai Khan sends the Polos back with a message, requesting that 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 and the important castle of Toron from the crusader states, and defeating the Armenians at Cilicia.
• Sang Sapurba and his younger brother Sang Ledhangwadja battled with Raidashir on top of Bukit Siguntang in Palembang. The brothers won and Sang Sapurba was proclaimed Maharaja.

  America

• In today's United States, a period of drought begins in the Four Corners Region, putting end to the ancient Puebloans Civilization.

  By topic

Economics

• In France, the gold écu and silver grosh coins are minted for the first time.

  Religion

• Ode de Pougy, Abbess of Notre Dame aux Nonnains, sends a gang to attempt to destroy the nearly-completed Church of St Urbain, Troyes.

  Births

• Hethum II of Armenia
• John of Brittany, Earl of Richmond
• Margaret of Villehardouin, Lady of Akova
• Rigdzin Kumaradza, Buddhist master
• Zhou Daguan, Mongol diplomat and geographer
• Duns Scotus, Scottish philosopher
• Herman VII, Margrave of Baden-Baden, nicknamed "The Clock"
• Jadwiga of Kalisz, Queen of Poland
• Ravivarman Kulaśēkhara, ruler of Venad

  Deaths

• January 11 - Swietopelk II, Duke of Pomerania
• February 12 - Amadeus of the Amidei, Italian saint
• February 26 - Manfred, King of Sicily
• June 12 - Henry II, Prince of Anhalt-Aschersleben
• August 4 - Eudes of Burgundy, Count of Nevers
• September 20 - Jan Prandota, Bishop of Kraków
• October 21 - Birger Jarl, Swedish regent and founder of Stockholm
• October 28 - Saint Arsenije I Sremac
• October 29 - Margaret of Austria, Queen of Bohemia
• December - John of Ibelin, jurist of the Kingdom of Jerusalem
• December 3 - Henry III the White, Duke of Wroclaw
• Berke, khan of the Golden Horde
• Hugh Bigod, Justiciar of England
• Ariq Böke, regent of the Mongol Empire
• Maol Choluim II, Earl of Fife
• Mo'ayyeduddin Urdi, Syrian astronomer and mathematician
• Nasiruddin Mahmud, sultan of Delhi