The Irish Free State (6 December 1922 – 29 December 1937), also known by its Irish name Saorstát Éireann (English: /ˌsɛərstɑːtˈɛərən/SAIR-staht AIR-ən, Irish:[ˈsˠiːɾˠsˠt̪ˠaːt̪ˠˈeːɾʲən̪ˠ]), was a state established in December 1922 under the Anglo-Irish Treaty of December 1921. The treaty ended the three-year Irish War of Independence between the forces of the Irish Republic—the Irish Republican Army (IRA)—and British Crown forces.