1173

Events

* Saint Thomas Becket is buried at Canterbury and canonized.
* Abergavenny Castle is seized by the Welsh.
* Peter Waldo is converted to Christianity and founds the Waldensians.
* End of Qiandao era and start of Chunxi era of the Chinese emperor Xiaozong.
* Casimir II of Poland succeeds Boleslaus IV of Poland on the throne.
* Eleanor of Aquitaine and her sons rebel against her husband Henry II of England in the Revolt of 1173–1174.
* Algebraic chess notation is first recorded.
* The Leaning Tower of Pisa is built.
* Saladin seizes Aden in Arabia.

Births

* Llywelyn the Great, Prince of Aberffraw and Lord of Eryri (approximate date; d. 1240)
* Rostislav II of Kiev (d. 1214)
* Shinran, Japanese founder of Jodo Shinshu Buddhism (d. 1263)
* Conrad II, Duke of Swabia (d. 1196)
* Tankei, Japanese sculptor (d. 1256)

Deaths

* August 9 — Najm ad-Din Ayyub, father of Saladin
* Roger de Clare, 3rd Earl of Hertford (b. 1116)
* Vladimir II Mstislavich, Grand Prince of Kiev (b. 1132)
* Boleslaus IV, High-Duke of Poland (b. 1120)
* Richard of St. Victor, French mystic and theologian
* Benoît de Sainte-Maure, French poet and troubadour (b. 1154)