Provisions by which Northern Ireland left the Irish Free State

Article 12 of the Anglo-Irish Treaty
''This is the text of the first sentence of Article 12 of the “Articles of Agreement for a Treaty between Great Britain and Ireland” as signed in London on 6 December 1921 (the “Treaty”). The Treaty was ratified in the United Kingdom for all purposes except one under the “Irish Free State (Agreement) Act, 1922”. The one purpose the Treaty was not ratified for under that Act was for the purpose of the date from which the “month” referred to in Article 11 of the Treaty would begin (the “Ulster Month”). The “Ulster Month” was the month within which the Houses of Parliament of Northern Ireland could present an Address to the King to the effect that the powers of the Parliament and Government of the Irish Free State should no longer extend to Northern Ireland and upon receipt of such an Address by the King the powers of the Parliament and Government of the Irish Free State would no longer extend to Northern Ireland.''

If before the expiration of the said month [the Ulster Month] an address is presented to His Majesty by both Houses of the Parliament of Northern Ireland to that effect, the powers of the Parliament and the Government of the Irish Free State shall no longer extend to Northern Ireland, and the provisions of the Government of Ireland Act, 1920, (including those relating to the Council of Ireland) shall so far as they relate to Northern Ireland, continue to be of full force and effect, and this instrument shall have effect subject to the necessary modifications.

Section 5 of the Irish Free State Constitution Act 1922
''This is the text of Section 5 of the Irish Free State Constitution Act 1922. It set the date from which the “Ulster Month” would begin - being the date this Act became law, 6 December 1922.''

This Act may be cited as the Irish Free State Constitution Act, 1922 (Session 2), and shall be deemed to be the Act of Parliament for the ratification of the said Articles of Agreement as from the passing whereof the month mentioned in Article eleven of the said Articles is to run.

The British King's message concerning the Anglo-Irish Treaty
The text of the telegram sent by the King of the United Kingdom of Great Britain and Ireland to his Prime Minister on 6 December 1921 following the signing of the Anglo-Irish Treaty on 6 December 1922.

I am overjoyed to hear the splendid news you have just sent me. I congratulate you with all my heart on the successful termination of these difficult and protracted negotiations, which is due to the patient and conciliatory spirit which you have shown throughout.

I am indeed happy in some small way to have contributed by my speech at Belfast to this great achievement.

GEORGE, R.I.

The Address of the Houses of Parliament of Northern Ireland
This is the text of the Address which was unanimously adopted by the Houses of Parliament of Northern Ireland on 7 December 1922 (the day after the establishment of the Irish Free State)

MOST GRACIOUS SOVEREIGN, We, your Majesty's most dutiful and loyal subjects, the Senators and Commons of Northern Ireland in Parliament assembled, having learnt of the passing of the Irish Free State Constitution Act, 1922, being the Act of Parliament for the ratification of the Articles of Agreement for a Treaty between Great Britain and Ireland, do, by this humble Address, pray your Majesty that the powers of the Parliament and Government of the Irish Free State shall no longer extend to Northern Ireland.

The King’s Acknowledgement of the Address
This is the text of the King's response given on 8 December 1922 at York Cottage, Sandringham House following his receipt the same day of the Address

I have received the Address presented to me by both Houses of the Parliament of Northern Ireland in pursuance of Article 12 of the Articles of Agreement set forth in the Schedule to the Irish Free State (Agreement) Act, 1922, and of Section 5 of the Irish Free State Constitution Act, 1922, and I have caused my Ministers and the Irish Free State Government to be so informed.