Events

• April 26 - The Gothic chapel Sainte-Chapelle is consecrated in Paris, France.
• August 15 - The foundation stone of the Cologne cathedral is laid after an older cathedral on the site burns down on April 30. Construction is completed 632 years later, in 1880.
• King Louis IX of France launches the Seventh Crusade, leading an army of 20,000 toward Egypt.
• Reconquista: King Ferdinand III of Castile recaptures the city of Seville from the Moors.
• Roger Bacon publishes the formula for black powder in Europe.
• Pope Innocent IV grants the Croats permission to use their own language and script in liturgy (see Glagolitic alphabet).
• Construction on the Alhambra palace, in Granada, Spain, is begun by the Moors.
• The University of Piacenza is founded.
• Tallinn (Reval) receives the Lübeck Rights.
• The Dutch city of Ommen receives city rights and fortification rights from Otto III, Archbishop of Utrecht on August 25.
• The Aztec Empire is established.

Births

• Blanche of Artois, regent of Navarre (approximate date) (d. 1300)
• Robert II, Duke of Burgundy (d. 1306)
• King Charles II of Naples (approximate date)
• Peter Olivi, Franciscan theologian

Deaths

• January 4 - King Sancho II of Portugal
• February 1 - Henry II, Duke of Brabant (b. 1207)
• Adachi Kagemori, Japanese samurai
• Güyük Khan, ruler of the Mongol Empire
• King Harald of the Isle of Man
• Subutai, Mongol general