The course of events between the Act of Union and the onset of partition has been so well recorded and analysed by generations of historians that I need not describe it in detail. For all of the nineteenth and the early years of the twentieth century, Britain agonised about its handling of its Irish inheritance. The late onset of Catholic emancipation, the experience of famine and emigration, the constant swings of policy between coercion and concession, and the eroding resistance to afford Ireland or most of it real Home Rule or independence; all contributed to a progressive alienation of much of Ireland alongside a growing fear by Ulster Protestants of submergence in a predominantly Catholic state.

The Government of Ireland Act, enacted in 1920, followed a ‘stay’ on constitutional development imposed for the duration of the First World War. The legislation, accepting the reality that Ulster could not conceivably be coerced – having regard in particular to the suffering of its sons at the Somme in 1916 – sought to establish, within the framework of a continuing United Kingdom, separate Parliaments and Governments for ‘Northern Ireland’ (six counties in the north-east of the island) and ‘Southern Ireland’ (the remaining twenty-six counties including three in Ulster) respectively.

It was a very strange anomaly in the outcome that Home Rule was, however reluctantly, accepted by that community within Ulster which had traditionally opposed it, and that, when finally offered it, that community in the rest of Ireland which had sought it for so long was no longer ready to accept it. Because the new powers of government and administration had to be both offered and accepted, the Act of 1920 was never to operate as those who framed it had hoped or intended. It was certainly not designed to be an instrument for the total separation or exclusion of Ireland from the United Kingdom. Nor did it envisage – even in the context of Ireland's continuing involvement in the United Kingdom – a final, permanent or irrevocable separation between the two parts of Ireland as the Act defined and distinguished them.