Timeline of the Irish War of Independence

The Irish War of Independence (or the Anglo-Irish War) of 1919–1921 was a guerrilla conflict, and most of the fighting was conducted on a small scale by the standards of conventional warfare. Although there were some large-scale encounters between the Irish Republican Army (IRA) and the state forces of the United Kingdom (Royal Irish Constabulary (RIC)/Auxiliary Division and Dublin Metropolitan Police (DMP) paramilitary units—the Black and Tans, the Ulster Special Constabulary (USC) and the regular British Army), most of the casualties were inflicted in assassinations and reprisals on either side.

Source: Wikipedia — Timeline of the Irish War of Independence (CC BY-SA 4.0)