||Wikimedia Commons has media related to 1237.
Year 1237 (MCCXXXVII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar.
- Thomas II of Savoy becomes count of Flanders.
- Elbing is founded in the State of the Teutonic Order (today Elbląg, Poland).
- After turning aside south for 15 years to invade the Caucasus, Asia Minor and Persia, Batu Khan (with representatives of all 4 khanates leading 150,000 Mongol, Turkish and Persian troops into Europe) resumes the European invasion, with the resumption of the Mongol invasion of Rus' foreshadowed thereby.
- December 21 – Mongol invasion of Rus': Ryazan is sacked.
- Gualdo Tadino, Italy, is destroyed by fire.
- The County of Artois is founded in France.
- Baldwin II becomes Latin Emperor of Constantinople.
- Conrad IV of Germany becomes King of Germany.
- Livonian Crusade: After their defeat in the Battle of Saule, the Livonian Brothers of the Sword are absorbed into the Teutonic Order, as the autonomous Livonian Order. An Estonian rebellion begins on Saaremaa Island.
- Battle of Cortenuova: Frederick II, Holy Roman Emperor defeats the Lombard League.
- A major fire destroys some 30,000 dwellings in the Chinese capital city of Hangzhou.