|Centuries:||12th century – 13th century – 14th century|
|Decades:||1210s 1220s 1230s – 1240s – 1250s 1260s 1270s|
|Years:||1246 1247 1248 – 1249 – 1250 1251 1252|
- King Louis IX of France captures Damietta in Egypt. It is the first major military battle of the Seventh Crusade.
- Pho Khun Si Indrathit is the first king of the Sukhothai kingdom. This is the start of the modern Thai nation.
- The Hikitsuke, a judicial organ of the Kamakura and Muromachi shogunates of Japan, is started.
- The Japanese Hōji era ends, and the Kenchō era begins.
- February 16 – Andrew of Longjumeau is sent by King Louis IX of France as an ambassador to meet with the Khan of the Mongols.
- June 13 – coronation of Alexander III as King of Scots.
- August 15 – The First Battle of Athenry is fought in Galway, Ireland.
- The city of Stralsund (in present-day Germany) is burned to the ground by forces from the rival city of Lübeck.
- Swedish statesman Birger Jarl takes over the province of Tavastia in Finland. This gives Sweden power in Finland.
- Alphonse of Toulouse orders Jews from Poitou, France to leave.
- The Hungarian capital is moved from Esztergom to Buda.
- May 26 – The Battle of Fossalta is fought between the Holy Roman Empire and the Lombard League. The Lombards capture the German commander.
- The Moors lose possession of Alicante in Al-Andalus (Islamic Spain).
- King Afonso III of Portugal recaptures Faro and Silves in the Algarve from the Moors. This ends the Portuguese Reconquista.
- The city of Mystras, Greece is strengthened and a palace is built there by William II Villehardouin.
- University College, the first College at Oxford, is founded with money gifted from the estate of William of Durham.
- July 6 – King Alexander II of Scotland (b. 1198)
- July 19 – Jacopo Tiepolo, Doge of Venice
- September 27 – Count Raymond VII of Toulouse (b. 1197)
- As-Salih Ayyub, ruler of Egypt
- Abu Zakariya, ruler of the Maghreb (b. 1203)
- William of Sherwood, English logician (b. 1190)
- Wuzhun Shifan, Chinese Zen Buddhist monk (b. 1178)
- Song Ci, Chinese physician and judge (b. 1186)