Since the 1870s, a concerted campaign had been made by Irish nationalist leaders at Westminster, in particular by Charles Stewart Parnell, to have Home Rule (regional self-government) introduced into Ireland.
For Unionists, the ultimate safeguard to prevent Home Rule had been the existence of the power of the House of Lords to veto legislation.
The Lords, with an inbuilt pro-Unionist Conservative Party majority, exercised its veto, in 1893, to block the Second Home Rule Bill.
In 1912, leader Bonar Law threatened to give support for whatever actions Unionists took, whether legal or illegal, to prevent home rule.
Faced with what seemed to be imminent civil war, King George – a strong Hibernophile since his days as a naval officer based in Cork – intervened to stop what be believed was the slide to civil war, and took the unprecedented step of inviting the leaders of both communities, along with the British government, to the Palace for a conference.
Those who attended were the Prime Minister H. H. Asquith, Lloyd George, the Irish Parliamentary Party leader John Redmond, his deputy, John Dillon, across the table the leader of the Irish Unionist Alliance, Edward Carson together with Bonar Law, James Craig and Lord Lansdowne.
Still, the basic reason for the actual 1922 partition was the same as for the one discussed at Buckingham Palace eight years before – i.e. the total refusal of the Ulster Unionists to become part of a predominantly Irish Catholic entity, whether or not under an overall British rule.
In 1920 he made clear his opposition to the behaviour of the Black and Tans paramilitary force being used by the British Government during the Irish War of Independence and unsuccessfully intervened to try to save the life of hunger striker Terence MacSwiney.