- Oliver Cromwell's troops land at Dublin to begin the conquest of Ireland.
- The Catholic Archbishop of Armagh is captured by Cromwell's troops and sent to the Tower of London.
- The Siege of Drogheda begins, resulting in the massacre of the town's population by Cromwell's forces.
- Dublin is captured by the Parliamentarian forces of Henry Ireton.
- Cromwell's campaign results in the surrender of numerous Catholic towns and castles, including Kilkenny and Waterford.
- The Act for the Settlement of Ireland is passed by the English Parliament, confiscating the lands of Irish rebels and granting them to English settlers.