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|Establishments – Disestablishments|
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- December – Third conflict in the Goryeo–Khitan War: The Liao Dynasty (Khitan Empire) invades Goryeo.
- A Chola Dynasty army invades Lanka with 150,000 troops (the largest amphibious invasion force in history to this date).
- January 30 – The Peace of Bautzen is signed between Henry II, Holy Roman Emperor, and Bolesław I Chrobry, Duke of Poland, ending the German–Polish War (1002–1018).
- July 22–23 – Battle of the River Bug: Bolesław I Chrobry, Duke of Poland, defeats Yaroslav the Wise. Yaroslav retreats to Novogrod, abandoning Kiev.
- July 29 – Battle of Vlaardingen: Dirk III, Count of Holland, defeats an army sent by Henry II, Holy Roman Emperor.
- August – The leader of the remaining Bulgarian resistance, Ivats, is treacherously blinded and captured by strategos Eustathios Daphnomeles, confirming Bulgaria's position as part of the Byzantine Empire.
- August 14 – Bolesław accepts the surrender of Kiev by the Pechenegs. He reinstates Sviatopolk as Grand Prince of Kiev.
- c. October? – Second Battle of Cannae: In Southern Italy, the Lombard adventurer Melus of Bari and his Norman mercenaries are decisively defeated by the Byzantine army, led by the Catepan Basil Boioannes.
- Probable date
- Battle of Carham: Máel Coluim mac Cináeda, King of Alba and Owain Foel, King of the Cumbrians are victorious over either Uhtred, son of Waltheof or Eadwulf Cudel, rulers of Bamburgh. The battle confirms Scottish dominance over Lothian.
- Cnut succeeds his brother Harald II of Denmark, on the Danish throne.
- April 10 – Nizam al-Mulk, Persian scholar and vizier (d. 1092)
- August 31 – Jeongjong II of Goryeo, Korean ruler (d. 1046)
- Harthacnut, King of Denmark (d. 1042)
- Michael Psellus, Greek philosopher and historian
- Richilde, Countess of Hainaut, Countess consort and Regent of Flanders (d. 1086)
- February 24 – Borrell, bishop of Vic
- June 23 – Henry I, Margrave of Austria
- Abd ar-Rahman IV, Umayyad caliph (murdered)
- Aeddan ap Blegywryd, King of Gwynedd
- Gerberga of Burgundy, German patron and duchess (b. ca 965) (approximate date)
- Harald II of Denmark, Danish monarch