|Ab urbe condita||1926|
|Balinese saka calendar||1094–1095|
|English Regnal year||19 Hen. 2 – 20 Hen. 2|
|Chinese calendar||壬辰年 (Water Dragon)|
3869 or 3809
— to —
癸巳年 (Water Snake)
3870 or 3810
|- Vikram Samvat||1229–1230|
|- Shaka Samvat||1094–1095|
|- Kali Yuga||4273–4274|
|Japanese calendar||Jōan 3|
|Minguo calendar||739 before ROC|
|Seleucid era||1484/1485 AG|
|Thai solar calendar||1715–1716|
1299 or 918 or 146
— to —
1300 or 919 or 147
|Wikimedia Commons has media related to 1173.|
- January 5 – Bolesław IV (the Curly), High Duke of Poland, dies after a 27-year reign. He is succeeded by his half-brother Mieszko III (the Old), and as duke of Sandomierz in Lesser Poland by Casimir II (the Just).
- King Canute I (Knut Eriksson) extends his rule after the death of co-ruler Kol – which includes also Östergötland. He becomes the unopposed sole-ruler of Sweden. Canute is supported by Earl Birger Brosa.
- Abu Yaqub Yusuf, caliph of the Almohad Caliphate, re-populates the western Andalusian city of Beja. But it is rapidly abandoned, a sign of the quick demographic weakening of the Muslims in the peninsula.
- Spring – Henry the Young King withdraws to the French court, marking the beginning of the Revolt of 1173–74, in which former Queen Eleanor of Aquitaine and her sons rebel against her ex-husband King Henry II.
- October 17 – Battle of Fornham: Rebel forces are defeated while fording the River Lark. Flemish mercenaries are driven into the nearby swamps by the English royalists under Lord Richard de Luci (or Lucy).
- Summer – Saladin leads an expeditionary army against the Bedouin tribes in Oultrejordain to secure a route between Egypt and Syria. He raids the region at Kerak Castle.
- Pro-Fatimid rising in Upper Egypt led by Kanz al-Dawla, governor of Aswan, is crushed by Saladin's brother Al-Adil.
- The Qiandao era ends and the Chunxi era begins during the reign of Emperor Xiao Zong of the Song Dynasty.
Art and LeisureEdit
- August 8 – The construction of a campanile, which will become the Leaning Tower of Pisa, begins.
- Algebraic chess notation is first recorded.
- King Béla III invites Cistercian and Premonstratensian monks to Hungary. They introduce advanced agricultural methods in the realm (approximate date).
- February 21 – Thomas Becket is canonized by Pope Alexander III. His tomb in Canterbury Cathedral becomes a shrine and a popular pilgrimage destination.
- Peter Waldo, French spiritual leader, is converted to Christianity and founds the Waldensians.
- The Great Mosque of al-Nuri in Mosul is completed (approximate date).
- May 21 – Shinran, founder of Shin Buddhism (d. 1263)
- December 23 – Louis I, duke of Bavaria (d. 1231)
- Diya al-Din al-Maqdisi, Arab Sunni scholar (d. 1145)
- Frederick I, count of Berg-Altena (approximate date)
- Isabella, countess of Gloucester (approximate date)
- Llywelyn the Great, king of Gwynedd (d. 1240)
- Rostislav II, Grand Prince of Kiev (d. 1214)
- Tankei, Japanese Buddhist sculptor (d. 1256)
- Walter Devereux, Norman nobleman (d. 1197)
- January 5 – Bolesław IV (the Curly), duke of Poland
- March 10 – Richard of Saint Victor, Scottish theologian
- August 9 – Najm ad-Din Ayyub, father of Saladin
- August 13 – Nerses IV, Catholicos of Armenia (b. 1102)
- October 15 – Petronilla, queen of Aragon (b. 1136)
- November 7 – Uijong, Korean ruler Goryeo (b. 1127)
- Benjamin of Tudela, Spanish Jewish traveler (b. 1130)
- Benoît de Sainte-Maure, French poet and writer
- Fujiwara no Ikushi, Japanese empress (b. 1146)
- Hemachandra, Indian poet and polymath (b. 1088)
- Kol of Sweden, Swedish ruler of Östergötland
- Narasimha I, Indian ruler of the Hoysala Empire
- Raimbaut d'Aurenga, French troubadour (b. 1147)
- Rajaraja II, Indian ruler of the Chola Dynasty
- Reginald Fitzurse, English nobleman (b. 1145)
- Roger de Clare, 2nd Earl of Hertford (b. 1116)
- Vladimir III, Grand Prince of Kiev (b. 1132)
- Picard, Christophe (2000). Le Portugal musulman (VIIIe-XIIIe siècle): L'Occident d'al-Andalus sous domination islamique. Paris: Maisonneuve & Larose. p. 110. ISBN 2-7068-1398-9.
- Beeler, John (1971). Warfare in Feudal Europe, 730–1200, pp 104–105. Ithaca, NY: Cornell University Press. ISBN 0-8014-9120-7.
- David Nicolle (2011). Osprey: Command 12 - Saladin, p. 4. ISBN 978-1-84908-317-1.
- Palmer, Alan; Veronica (1992). The Chronology of British History. London: Century Ltd. pp. 69–72. ISBN 0-7126-5616-2.