- February 14: Pope Benedict VIII recognizes and crowns Henry of Bavaria (who has ruled since 1003) as King of Germany.
- April 23: Battle of Clontarf: Gaelic Irish forces under Brian Boru defeat several allied Viking forces in Ireland, ending their power there but losing Brian in the battle.
- July 29: Battle of Kleidion: Basil II inflicts not only a decisive defeat on the Bulgarian army, but his subsequent savage treatment of 15,000 prisoners reportedly causes Tsar Samuil of Bulgaria to die of shock, and earns Basil II the title 'Voulgaroktonos' (Bulgar-slayer).
- Following the death of Sweyn I, Ethelred II returns to England and retakes the English crown.
- Canute the Great returns to Denmark.
- Holmgang is declared illegal in Norway.
- The Nicene Creed is used for the first time during the Roman Mass after Henry II, the newly crowned Holy Roman Emperor, asks the Pope to add it together with the filioque clause. Prior to this date, the Creed was not used at all during the liturgy.
- In England, Archbishop Wulfstan preaches his Latin homily, "Wulf's Address to the English".