The Anglo-Irish Treaty (Irish: An Conradh Angla-Éireannach), commonly known as The Treaty and officially the Articles of Agreement for a Treaty Between Great Britain and Ireland, was an agreement between the government of the United Kingdom of Great Britain and Ireland and representatives of the Irish Republic that concluded the Irish War of Independence. It provided for the establishment of the Irish Free State within a year as a self-governing dominion within the 'community of nations known as the British Empire', a status 'the same as that of the Dominion of Canada'. It also provided Northern Ireland, which had been created by the Government of Ireland Act 1920, an option to opt out of the Irish Free State, which it exercised.