Bloody Sunday () was a day of violence in Dublin on 21 November 1920, during the Irish War of Independence. In total, 31 people were killed – fourteen British, fourteen Irish civilians and three republican prisoners. The day began with an Irish Republican Army (IRA) operation to assassinate the Cairo Gang, a team of undercover agents working and living in Dublin. Twelve were British Army officers, one a member of the Royal Irish Constabulary and the last a civilian informant.