|Covid-19|April 21 – Santiago de Compostela Cathedral (begun in the 11th century) is consecrated in the presence of king Alfonso IX of León.
September 14 – Canons Regular of the Order of the Holy Cross are founded in Liège.
October 15 – Latin emperor Henry of Flanders defeats the Nicaean emperor Theodore I Lascaris in the Battle of the Rhyndacus.
Livonian Crusade: The crusaders fail to conquer Viljandi stronghold, but achieve to baptize Sakala and Ugandi counties in Southern Estonia.
Mongol forces under Genghis Khan invade the Jurchen-led Jin dynasty of northern China, aiming at this stage simply to loot the countryside. A Jin army is defeated and slaughtered at the Battle of Yehuling near Zhangjiakou and another is beaten at Mukden, where the city is taken. Zhongdu is also besieged by the Mongol hordes.
The church in the French city of Reims burns down; soon after, construction begins on Reims Cathedral.
King John of England sends a gift of herrings to nunneries in almost every shire despite his status as an excommunicant.
The oldest extant double-entry bookkeeping system record dates from this year.
September 22 – Ibn Khallikan, Kurdish Muslim scholar (d. 1282)
William of Villehardouin, prince of Achaea (d. 1278)
August 9 – William de Braose, 4th Lord of Bramber, exiled Anglo-Norman baron (b. 1144/53)
Kaykhusraw I, Seljuk Sultan of Rûm (killed in battle)
Year 1211 (MCCXI) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar.