The Battle of Dublin was a week of street battles in Dublin from 28 June to 5 July 1922 that marked the beginning of the Irish Civil War. It was fought between the forces of the new Provisional Government, which supported the Anglo-Irish Treaty, and a section of the Irish Republican Army (IRA) who opposed the Treaty. The fighting began with an assault by Provisional Government forces on the Four Courts building, which had been occupied by the Anti-Treaty IRA, and ended in a decisive victory for the Provisional Government.