The Government of Ireland Act was passed on the 23rd December 1920 and partitioned Ireland with the six counties of Ulster (which had a Protestant majority) becoming Northern Ireland and the remaining 26 counties becoming Southern Ireland.

The Act was designed to create two Home Rule jurisdictions within Ireland, with provisions made for future unification through a Council of Ireland.

However, the War of Independence and the existence of Dáil Éireann meant that the proposed Dublin Home Rule parliament was never established in southern Ireland. In contrast, King George V opened the Northern Ireland parliament on the June 22nd, 1921 at Belfast City Hall.