1217

Events

• April 9 - Peter of Courtenay crowned emperor of the Latin Empire of Constantinople at Rome, by Pope Honorius III
• May 20 - First Barons' War, royalist victory at Lincoln.
• August 24 - First Barons' War, Battle of Sandwich between English and French soldiers in the English Channel - mercenary Eustace the Monk working for the French side, is captured and beheaded
• September 11 - Treaty of Lambeth ends First Barons' War.
• Kingdom of Serbia founded
• Fifth Crusade begins with a failed Christian attack to Egypt
• Genghis Khan destroys Kara-Khitai

Births

• Baldwin, future Latin Emperor of Constantinople
• Hulagu Khan, Mongol ruler (d. 1265)
• John I, Duke of Brittany

Deaths

• Lembitu - Leader of the Estonian resistance to the Northern Crusades

Monarchs/Presidents

• France - Philippe II, Auguste King of France (reigned from 1180 to 1223)
• Holy See - Honorius III pope (from 1216 to 1227)
• Mongol Empire - Genghis Khan, Mongol Khan (from 1206 to 1227)
• Venice - Pietro Ziani Doge of Venice (ruled from 1205 to 1229)