|Ab urbe condita||1847|
|Balinese saka calendar||1015–1016|
|English Regnal year||7 Will. 2 – 8 Will. 2|
|Chinese calendar||癸酉年 (Water Rooster)|
3790 or 3730
— to —
甲戌年 (Wood Dog)
3791 or 3731
|- Vikram Samvat||1150–1151|
|- Shaka Samvat||1015–1016|
|- Kali Yuga||4194–4195|
|Japanese calendar||Kanji 8 / Kahō 1|
|Minguo calendar||818 before ROC|
|Seleucid era||1405/1406 AG|
|Thai solar calendar||1636–1637|
1220 or 839 or 67
— to —
1221 or 840 or 68
- Spring – Emperor Alexios I (Komnenos) sends a Byzantine expeditionary force under General Tatikios to Nicaea, in an attempt to re-capture the city from the Seljuk Turks. However, the arrival of Barkiyaruq's army en route stops the Byzantines. Alexios sends reinforcements; short of supplies, the Seljuk Turks retreat. Abu'l-Qasim, Seljuk governor of Nicaea, is defeated and forced to conclude a truce with Alexios.
- May – Rodrigo Diaz de Vivar (El Cid) completes his conquest of Valencia in Al-Andalus (modern Spain). He begins his rule (in the name of King Alfonso VI) of Valencia. The Almoravid campaign to regain the city fails.
- July 28 – William Bertrand dies, and his margravial title of Provence is inherited by Raymond IV (Saint-Gilles), who becomes count of Toulouse (until 1105).
- May – Duncan II (son of the late King Malcolm III) invades England at the head of an army of Norman knights Scotland, aided by his half-brother Edmund. He succeeds his uncle, King Donald III (the Fair), as ruler of Scotland.
- November 12 – King Donald III mobilizes his army and kills Duncan II in battle in the Lowlands. He re-takes the Scottish throne, Edmund sides with Donald as co-ruler and is named as heir as he has no children.
- Sultan Mahmud I dies after a 2-year reign. He is succeeded by his brother Barkiyaruq (one of the Seljuk prince who claim the throne) as ruler of the Seljuk Empire.
- January 14 – Eudokia Komnene, Byzantine princess (d. 1129)
- Abd al-Mu'min, Almohad caliph (approximate date)
- Ibn Zuhr (or Avenzoar), Moorish physician (d. 1162)
- Malachy, Irish archbishop and saint (d. 1148)
- Richard d'Avranches, 2nd Earl of Chester (d. 1120)
- Yelü Dashi, founder of the Qara Khitai (d. 1143)
- January 10 – Al-Mustansir Billah, Fatimid caliph (b. 1029)
- February 3
- June 2 – Nicholas the Pilgrim, Italian shepherd (b. 1075)
- June 4 – Sancho V, king of Aragon and Pamplona
- July 28 – William Bertrand, margrave of Provence
- October 14
- November 12 – Duncan II, king of Scotland
- Abu Ali Fana-Khusrau, Buyid nobleman
- Al-Bakri, Moorish historian and geographer
- Aq Sunqur al-Hajib, Seljuk sultan of Aleppo
- Badr al-Jamali, Fatimid vizier and statesman
- Isaac Albalia, Andalusian Jewish astronomer (b. 1035)
- Jonathan I, Italo-Norman count of Carinola
- Mahmud I, sultan of the Seljuk Empire
- Michael of Avranches, Italian bishop
- Roger de Beaumont, Norman nobleman
- Roger de Montgomery, Norman nobleman
- Terken Khatun, Seljuk empress and regent
- William Fitzeustace, Norman nobleman
- Wulfnoth Godwinson, English nobleman
- Timothy Venning (2015). A Chronology of the Crusades, p. 24. ISBN 978-1-138-80269-8.
- Picard C. (1997). La mer et les musulmans d'Occident au Moyen Age. Paris: Presses Universitaires de France.
- Potter, Philip J. (2009). Gothic Kings of Britain: The Lives of 31 Medieval Rulers (1016–1399), pp. 127–128. Jefferson, North Carolina: McFarland. ISBN 978-0-7864-4038-2.