1234
Year 1234 was a common year starting on Sunday of the Julian calendar.
File:Bataille entre mongols & chinois.jpeg|upright=1.35|thumb|Battle between Mongol warriors and Jin horsemen, during the Mongol conquest of the Jin dynasty from the Jami' al-tawarikh, by Rashid al-Din Hamadani
Events
By place
Europe
- King Canute II of Sweden dies after a five-year reign. His rival, Eric XI, returns as ruler of Sweden. It is also possible that Canute dies of natural causes, and Eric peacefully then returns as king.
- King Andrew II of Hungary proclaims his son, Coloman of Galicia, as ruler of Bosnia and Herzegovina in [the Middle Ages|Bosnia], who passes it on to Prijezda, a cousin of Matej Ninoslav, despite Matej being the legitimate ruler.
- Reconquista - King Sancho II of Portugal conquers the cities of Aljustrel and Mértola from the Moors.
Mongol Empire
- February 9 - Mongol conquest of the Jin dynasty: The Mongol army led by Ögedei Khan captures the Jin capital at Caizhou, after the two-month Siege of Caizhou). Emperor Aizong of Jin abdicates the throne to Wanyan Chenglin, a descendant of the Jin imperial clan. After the Mongol and Song forces have breached the city walls, Aizong tries to escape, but commits suicide to avoid being captured. This marks the end of the Jin dynasty in China.
Africa
- The Manden region rises against the Kaniaga Kingdom. This is the beginning of a process that will lead to the rise of the Mali Empire.
By topic
Religion
- November - Pope Gregory IX proclaims war on the city of Rome after a local revolt forces him into exile. He issues the papal bull Rachel suum videns, calling for a new crusade to the Holy Land.
- Lund Cathedral in Sweden is heavily damaged in a catastrophic fire. Large donations are made to the church, to rebuild the cathedral.