|Ab urbe condita||2001|
|Balinese saka calendar||1169–1170|
|English Regnal year||32 Hen. 3 – 33 Hen. 3|
|Chinese calendar||丁未年 (Fire Goat)|
3944 or 3884
— to —
戊申年 (Earth Monkey)
3945 or 3885
|- Vikram Samvat||1304–1305|
|- Shaka Samvat||1169–1170|
|- Kali Yuga||4348–4349|
|Japanese calendar||Hōji 2|
|Minguo calendar||664 before ROC|
|Thai solar calendar||1790–1791|
1374 or 993 or 221
— to —
1375 or 994 or 222
|Wikimedia Commons has media related to 1248.|
- 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 (construction is completed 632 years later, in 1880).
- 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.
- 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 (see Glagolitic alphabet).
- Tallinn (Reval) 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 (in modern-day Mexico City).
- Tezcapoctzin becomes Ruler of the City-state Azcapotzalco at the Valley of Mexico
- January 4 – King Sancho II of Portugal (b. 1209)
- February 1 – Henry II, Duke of Brabant (b. 1207)
- March 27 – Maud Marshal, English countess (b. 1192)
- April 20 – Güyük Khan, ruler of the Mongol Empire (b. 1206)
- June 11 – Adachi Kagemori, Japanese samurai