1252

Events

Europe

* May 15 - Pope Innocent IV issues the papal bull "Ad exstirpanda", which authorizes the torture of heretics in the Medieval Inquisition. Torture quickly gains widespread usage 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 incorporated into the German state of Brandenburg, marking the start of Brandenburg's expansion into previously Polish areas (Neumark).
* The Swedish city of Stockholm is founded by Birger Jarl.
* The Lithuanian city of Klaipėda ("Memel") is founded by the Teutonic Knights.
* The town and monastery of Orval in Belgium burn to the ground; rebuilding takes 100 years.
* Thomas Aquinas travels to the University of Paris to begin his studies there for a masters degree.
* In astronomy, work begins on the recording of the Alfonsine tables.

Asia

* The classic Japanese text "Jikkunsho" is completed.
* The Chinese era "Chunyou" ends.
* The Mongols take the westernmost province of the Song Dynasty empire.

Births

* March 25 - Conradin, Duke of Swabia (d. 1268)
* Safi Al-Din, Persian Sufi leader
* Amadeus V of Savoy (d. 1323)
* Eleanor de Montfort, princess of Wales (d. 1282)

Deaths

* March 6 - Saint Rose of Viterbo, Italian saint (b. 1235)
* May 30 - King Ferdinand III of Castile and Leon
* June 29 - King Abel of Denmark (b. 1218)
* November 26 - Blanche of Castile, queen of Louis VIII of France and regent of France (b. 1188)
* Queen Isabella of Armenia
* Sorghaghtani Beki, Mongolian empress and regent
* Giovanni da Pian del Carpini, Italian chronicler of the Mongol Empire
* Theobald IV of Champagne (b. 1201)