The Government of Ireland Act 1920 received the royal assent from King George V a century ago last month. This most consequential of acts resulted in the partition of Ireland. The genesis of the Government of Ireland Act 1920 came in 1919.
Home Rule had been on the statute book since 1914 and could no longer be postponed. It was scheduled to come into operation automatically when hostilities were formally concluded with the signature of the last of the peace treaties after the First World War.
To prevent this, the Prime Minister, David Lloyd George, set up a committee, chaired by Cabinet member Walter Long, to draft the Government of Ireland Bill.
The make-up of Long's committee was unionist in outlook. There was no nationalist representation whatsoever, nor was the advice of any nationalists sought. Leading Ulster unionist James Craig and his associates were the only Irishmen consulted.
Long's committee proposed to create two distinct legislatures for Ulster and the southern provinces, linked by a common council, comprising representatives from both.
This was the first time a British government proposed a separate parliament for Ulster.
Before the end of the war, the exclusion of Ulster, or at least some of Ulster, was the only option being considered in terms of special treatment for the province.
Ulster unionists desired for direct rule to remain from Westminster.
The common council proposed in the Government of Ireland Bill was a Council of Ireland to be composed of 20 members from each parliament, which the British stated could lead to "the peaceful evolution of a single parliament for all Ireland".
Initially, there were many objections from Ulster unionists.
The main problem was with the area to be included in the Ulster parliament: Ulster unionists sought the six counties of Antrim, Armagh, Derry, Down, Fermanagh and Tyrone, and not the nine counties of Ulster proposed by Long's committee, as this was the maximum area they felt they could dominate without being "outbred" by Catholics.
This decision of the Ulster Unionist Council was deeply unpopular among the 70,000 Protestants of counties Donegal, Cavan and Monaghan, who were sacrificed to the southern administration.
Belfast unionist MP Thomas Moles explained that the three counties had to be abandoned in order to save the Six Counties: "In a sinking ship, with lifeboats sufficient for only two-thirds of the ship's company, were all to condemn themselves to death because all could not be saved?"
Even though the Ulster Unionist Council endorsed the Government of Ireland Bill reluctantly, many Ulster unionists eventually "concluded that the scheme proposed in the Government of Ireland Act would cause the least diminution of their Britishness".
Some, such as James Craig's brother, Charles, began to see the great benefits Ulster unionists would garner from having their own parliament: "The Bill practically gives us everything that we fought for, everything we armed ourselves for."
It has often been cited that the Government of Ireland Bill was allowed to pass relatively unchallenged due to the vacuum in nationalist representation at Westminster.
With Sinn Fein abstaining, there were just seven Irish nationalist MPs remaining in Westminster (six from Ireland and TP O'Connor from Liverpool) after the 1918 general election, instead of 80.
It could be argued that even 80 nationalist MPs would have made little difference, considering the make-up of the House of Commons after the election. The Conservative Party, Lloyd George's Coalition Liberal Party and Irish unionists won over 500 seats, an overwhelming majority.
It is doubtful that Sinn Fein's presence would have made a difference.
What little voice the seven nationalist MPs had was further diminished by the Catholic Church's belief that they should not participate in the committee stages, nor suggest amendments to the Government of Ireland Bill.
The Catholic Church was virulently opposed to partition and believed that participating in the framing of the "Partition Bill" would be seen as a sign of its acceptance.
The Bishop of Derry, Charles McHugh, claimed Catholic Ulster would never submit to "become hewers of wood and drawers of water for Sir Edward Carson".
The leading nationalist MP left in Westminster, Joseph Devlin, condemned the Bill as "conceived in Bedlam", "ridiculous" and "fantastic". He voted against it, but did not contribute to its final shape.
With Sinn Fein's policy on partition almost non-existent, it chose to ignore the Government of Ireland Bill.
As the Bill was making its way through parliament, the British government was waging a war with Sinn Fein and its military wing, the IRA.
Sinn Fein leaders stuck steadfastly - and naively - to the view that Ulster would readily come into an all-Ireland parliament once Britain was removed from the island.
That the Government of Ireland Act came into law as Britain was at open war with Sinn Fein, supported by a considerable majority on the island, shows the total air of unreality that surrounded the Act.
In granting the royal assent to the Government of Ireland Act 1920, King George V expressed the hope that it, "the fruit of more than 30 years of ceaseless controversy, will finally bring about unity and friendship between all the peoples of my kingdom".
This was a wildly optimistic reading of the environment in Ireland in 1920 and of the likely fallout from its impending partition.
Cormac Moore is the author of Birth of the Border: The Impact of Partition in Ireland (Merrion Press, £19.99)