<P> In January 1919, after the December 1918 general election, 73 of Ireland's 106 Members of Parliament (MPs) elected were Sinn Féin members who refused to take their seats in the British House of Commons . Instead, they set up an Irish parliament called Dáil Éireann . This first Dáil in January 1919 issued a Declaration of Independence and proclaimed an Irish Republic . The Declaration was mainly a restatement of the 1916 Proclamation with the additional provision that Ireland was no longer a part of the United Kingdom . The new Irish Republic was recognised internationally only by the Russian Soviet Republic . The Irish Republic's Aireacht (Ministry) sent a delegation under Ceann Comhairle (Head of Council, or Speaker, of the Daíl) Seán T. O'Kelly to the Paris Peace Conference of 1919, but it was not admitted . </P> <P> After the War of Independence and truce called in July 1921, representatives of the British government and the Irish treaty delegates, led by Arthur Griffith, Robert Barton and Michael Collins, negotiated the Anglo - Irish Treaty in London from 11 October to 6 December 1921 . The Irish delegates set up headquarters at Hans Place in Knightsbridge and it was here in private discussions that the decision was taken on 5 December to recommend the treaty to Dáil Éireann . The Second Dáil Éireann narrowly ratified the Treaty . </P> <P> In accordance with the treaty, on 6 December 1922 the entire island of Ireland became a self - governing dominion called the Irish Free State (Saorstát Éireann). Under the Constitution of the Irish Free State, the Parliament of Northern Ireland had the option to leave the Irish Free State one month later and return to the United Kingdom . During the intervening period, the powers of the Parliament of the Irish Free State and Executive Council of the Irish Free State did not extend to Northern Ireland . Northern Ireland exercised its right under the treaty to leave the new dominion and rejoined the United Kingdom on 8 December 1922 . It did so by making an address to the King requesting, "that the powers of the Parliament and Government of the Irish Free State shall no longer extend to Northern Ireland ." The Irish Free State was a constitutional monarchy sharing a monarch with the United Kingdom and other dominions of the British Commonwealth . The country had a governor - general (representing the monarch), a bicameral parliament, a cabinet called the "Executive Council", and a prime minister called the President of the Executive Council . </P> <P> The Irish Civil War was the consequence of the creation of the Irish Free State . Anti-treaty forces, led by Éamon de Valera, objected to the fact that acceptance of the treaty abolished the Irish Republic of 1919 to which they had sworn loyalty, arguing in the face of public support for the settlement that the "people have no right to do wrong". They objected most to the fact that the state would remain part of the British Empire and that members of the Free State Parliament would have to swear what the Anti-treaty side saw as an oath of fidelity to the British King . Pro-treaty forces, led by Michael Collins, argued that the treaty gave "not the ultimate freedom that all nations aspire to and develop, but the freedom to achieve it". </P>

When did the south of ireland became independent from britain