The Irish Oath of Allegiance was a controversial provision in the Anglo-Irish Treaty of 1921, which Irish TDs (members of the Irish parliament) and Senators were required to take, in order to take their seats in Dáil Éireann (The Chamber of Deputies) and Seanad Éireann (the Irish Senate). The Oath was included in Article 17 of the Irish Free State's 1922 Constitution.
- I ... do solemnly swear true faith and allegiance to the Constitution of the Irish Free State as by law established, and that I will be faithful to H.M. King George V, his heirs and successors by law in virtue of the common citizenship of Ireland with Great Britain and her adherence to and membership of the group of nations forming the British Commonwealth of nations.
The Oath was widely condemned by the anti-treaty campaigners as involving Irish politicians taking an Oath of Allegiance to the British King. However, as the wording shows, that was an incorrect interpretation.
- The Oath of Allegiance was actually 'to the Irish Free State as by law established (a line drafted ironically by de Valera in his own proposed oath). The reference to the King involved a promise of fidelity, not an Oath of Allegiance.
- The fidelity to the King was not to him as British monarch but 'in virtue of the common citizenship of Ireland with Great Britain and her adherence to and membership of the group of nations forming the British Commonwealth of nations', in other words, in his role as the symbol of the Treaty settlement, not as British King.
When de Valera founded Fianna Fáil in 1926, he and his party, though agreeing to contest elections, refused to take the Oath. However the assassination of the Vice-President of the Executive Council (deputy prime minister), Kevin O'Higgins led the Cumann na nGaedhael government under W.T. Cosgrave to introduce a law requiring all Dáil candidates to promise that they would take the Oath. Otherwise they could not contest the election. Backed into a corner, de Valera took the Oath, declaring that he was simply signing a piece of paper to be admitted to the Dáil. In power from 1932, de Valera amended the Free State's constitution firstly to allow him to introduce any constitutional amendments irrespective of whether they clashed with the Anglo-Irish Treaty, then amended the constitution to remove Article 17 of the constitution which required the taking of the Oath.