This article may have too many red links. (April 2012)
|Centuries:||12th century – 13th century – 14th century|
|Decades:||1220s 1230s 1240s – 1250s – 1260s 1270s 1280s|
|Years:||1249 1250 1251 – 1252 – 1253 1254 1255|
- May 15– Pope Innocent IV issues the papal bull Ad exstirpanda, which allows the torture of heretics in the Medieval Inquisition. Torture is soon used widely across Catholic Europe.
- The first European gold coins are minted in the Italian city of Florence, and are known as florins.
- The Polish land of Lebus is made a part of the German state of Brandenburg, beginning Brandenburg's expansion into previously Polish areas (Neumark).
- The Swedish city of Stockholm is founded by Birger Jarl.
- The Lithuanian city of Klaipėda is founded by the Teutonic Knights.
- The town and monastery of Orval in Belgium burns to the ground; rebuilding takes 100 years.
- Thomas Aquinas travels to the University of Paris to begin his studies there for a master's degree.
- In astronomy, work begins on the recording of the Alfonsine tables.