1211 is a year in the 13th century.
- The oldest extant double entry bookkeeping record dates from 1211
- Canons regular of the Order of the Holy Cross founded September 14 1211
- Troops led by Estonian resistance fighter Lembitu of Lehola destroy a garrison of missionaries in the historical Estonian region of Sakala and raid the Russian town of Pskov.
- Mongol forces under Ghengis Khan invade Jin China, aiming at this stage simply to loot the countryside. A Chinese army is defeated and slaughtered at the Battle of the Badger's Mouth near Zhangjiakou and another is beaten at Mukden, where the city is taken. Beijing is also besieged by the Mongol hordes.
- Church at the French city of Reims burns down; soon after, construction begins on the cathedral, Notre Dame de Reims.