1248
Year 1248 was a leap year starting on Wednesday of the Julian calendar.Events
- April 26 - The Gothic chapel Sainte-Chapelle is consecrated in Paris, France.
- August 15 - The foundation stone of Cologne Cathedral is laid, after an older cathedral on the site burns down on April 30.
- August 25 - The Dutch city of Ommen receives city rights and fortification rights from Otto III, Archbishop of Utrecht, after it has been pillaged at least twice by a local robber baron.
- November 23 - Reconquista: King Ferdinand III of Castile recaptures the city of Seville from the Moors, ending the Siege of Seville; this year also Prince Alfonso X of Castile takes the city of Alicante.
- November 24 - In the middle of the night a mass on the north side of Mont Granier suddenly collapses, in one of the largest historical rock slope failures known in Europe.
Date unknown
- King Louis IX of France launches the Seventh Crusade, setting sail with an army of 20,000 toward Egypt.
- Pope Innocent IV grants the Croats permission to use their own language and script in liturgy.
- Tallinn converts from Riga law to Lübeck law.
- Roger Bacon publishes the formula for black powder in Europe.
- Approximate date - History of the Aztecs: The Mexica tribe, predecessors of the Aztec people, arrive at Chapultepec.
- Tezcapoctzin becomes Ruler of the City-state Azcapotzalco at the Valley of Mexico
Births
- Blanche of Artois, queen consort and regent of Navarre
- Robert II, Duke of Burgundy
- Peter Olivi, Franciscan theologian
- Isabella of Aragon, queen of Philip III of France
Deaths
- January 4 - King Sancho II of Portugal
- February 1 - Henry II, Duke of Brabant
- March 27 - Maud Marshal, English countess
- April 20 - Güyük Khan, ruler of the Mongol Empire
- June 11 - Adachi Kagemori, Japanese samurai
- Haraldr Óláfsson, King of Mann and the Isles and his wife, Cecilía, daughter of Hákon Hákonarson, King of Norway
- Subutai, Mongol general
