It is one hundred years since the United Kingdom’s border on the island of Ireland was settled by an international treaty and legislation passed by the UK and Irish Parliaments.

This Insight looks at the background to the Irish Boundary Commission and the decision by the governments of Ireland, Northern Ireland and the UK to confirm the existing border in December 1925.

Why was the border unconfirmed in 1925?

The status of the border between Northern Ireland (a devolved part of the UK) and the then Irish Free State (later the Republic of Ireland) was left unsettled in the wake of the Anglo-Irish Treaty.

This treaty, agreed on 6 December 1921, took effect exactly a year later. At that point, the Irish Free State ceased to be part of the United Kingdom of Great Britain and Ireland and instead became an independent “Dominion” within the then British Empire. (A self-governing territory under the Crown.) The Government of Ireland Act 1920 had already partitioned the island with an administrative boundary between “Northern” and “Southern” Ireland.

Under Article 11 of the treaty, the devolved Parliament of Northern Ireland could decide to join the Free State or remain part of the UK. On 7 December 1922, it chose the latter.

This decision triggered Article 12 of the treaty, which provided for:

a Commission consisting of three persons, one to be appointed by the Government of the Irish Free State, one to be appointed by the Government of Northern Ireland and one, who shall be Chairman, to be appointed by the British Government shall determine in accordance with the wishes of the inhabitants, so far as may be compatible with economic and geographic conditions, the boundaries between Northern Ireland and the rest of Ireland.

The Irish Boundary Commission

Political disagreements delayed the formation of the Irish Boundary Commission.

The Irish Free State appointed its representative to the commission in July 1923, shortly after the Irish Civil War (fought between supporters and opponents of the Anglo-Irish Treaty) came to an end. The UK Government announced the appointment of the Welsh-born South African judge Richard Feetham as chairman on 5 June 1924. But Sir James Craig, the Ulster Unionist Prime Minister of Northern Ireland, refused to nominate his representative as he viewed the border established in 1921 as permanent.

This refusal was a “casus improvises”, an event unforeseen by the acts of Parliament which had given effect to the Anglo-Irish Treaty. The matter was referred to the Judicial Committee of the Privy Council, which concluded that the Anglo-Irish Treaty required amendment.

On 2 August 1924 the Free State and UK Governments met and agreed to amend the treaty. The Irish Free State (Confirmation of Agreement) Act 1924 received Royal Assent on 9 October 1924 and enabled the UK Government to appoint a representative (Joseph Fisher) on behalf of the Government of Northern Ireland.

The formation of the Irish Boundary Commission was announced in the London Gazette on 31 October 1924 and met for the first time in London a week later. Mr Justice Feetham interpreted the treaty as facilitating relatively minor transfers of territory between Northern Ireland and the Free State, largely based on religion.

The “award” (the new Irish boundary) was agreed at a series of commission meetings between 13 and 17 October 1925. An initial draft was approved on 5 November but two days later it was leaked to the Morning Post newspaper, complete with a map of the “rectified border”. The Free State was to gain 180,000 acres and 51,000 inhabitants from Northern Ireland, while 50,000 acres and 7,500 inhabitants were to be transferred from the Free State to Northern Ireland.

Confirming the border

The Free State Government had anticipated a much larger transfer of territory, while that of Northern Ireland said “not an inch” should be moved. Eoin MacNeill, the Free State’s representative, resigned from the Boundary Commission on 20 November. The UK Government also feared the “Irish Question” would once again dominate British politics.

As a result, on 3 December 1925 the leaders of the Free State, the Northern Ireland and the UK governments met in London and decided to suppress the Irish Boundary Commission’s report. They also agreed to further amend the Anglo-Irish Treaty of 1921, revoking Article 12 (thereby confirming the existing boundary) and, as a quid pro quo, releasing the Free State from an obligation under Article 5 to service a proportion of the UK’s public debt.

A preamble to the treaty amendment referred to the three governments aiding “one another in a spirit of neighbourly comradeship”. Unusually, the document was signed by representatives of the UK, Irish and Northern Irish governments, even though the last of those was a devolved administration and not party to the original 1921 treaty.

This treaty amendment required further legislation in the UK and Irish parliaments. The House of Commons debated the Ireland (Confirmation of Agreement) Bill on 8 December 1925. Prime Minister Stanley Baldwin said:

The award itself will not see the light. It will be presented to the [UK] Government and put away with their archives, for publication, possibly, in some future year, when, maybe, the Irish boundary itself will arouse about as much excitement in Ireland as Offa’s Dyke or Hadrian’s Wall between the component parts of this island.

The Boundary Commission’s report was not declassified until 1 January 1968, during the period known as “The Troubles” in Northern Ireland.

Meanwhile, the Ireland (Confirmation of Agreement) Act 1925 received Royal Assent on 10 December 1925. The Irish parliament also passed the Treaty (Confirmation of Amending Agreement) Act, 1925. These acts gave effect to the amended treaty.

The UK Parliament did not change its name (to the “Parliament of the United Kingdom of Great Britain and Northern Ireland”) until the Royal and Parliamentary Titles Act 1927 received Royal Assent in April 1927. King George V also proclaimed himself “King of Great Britain, Ireland” instead of “King of the United Kingdom of Great Britain and Ireland”. This remained the Monarch’s title until 1953 when the phrase “United Kingdom” was restored and “Ireland” changed to “Northern Ireland”.

Further reading

About the author: Dr David Torrance is a researcher at the House of Commons Library, specialising in devolution (including Northern Ireland).

Image: Irish Border by Flying Puffin under CC BY-SA 2.0