1121

Events 
 Concordat of Worms condemns Pierre Abélard's writings on the Holy Trinity. Later in the year, Canon Fulbert (not to be confused with Fulbert of Chartres (960-1028)), uncle of Heloise, has Abélard castrated.
 Reading Abbey is founded.
 David the Builder, King of Georgia, with the army of 55,000 defeats the 200,000-strong Muslim coalition troops at Didgori, Eastern Georgia.

 Deaths 
 December 11 — Al-Afdal Shahanshah, Caliph of Egypt (b. 1066)
 William of Champeaux, French philosopher
 Zhou Tong, archery teacher and second military arts tutor of famous Song Dynasty General Yue Fei.