I also think the death of De Valera in the early 70's allowed Ireland to open up economically. Dev seems to have been obssesed with the idea of Ireland being primarily a rural,agricultural nation.
Give the man a pack of Tayto C&O. His Gaelic Nationalism was a disaster.
Religion,frankly. The Protestents in Ulster were always treated much better then the Catholics in the rest of Ireland.
I think the partition was probably inevitable. No way were the Protestent Majority in Ulster going to voluntary join a Predomntly Catholic Government,and to try to coerce them would have resulted in a even greater blood bath. This has always been the weakness of the Pure Irish Republican VIew:just did not accept that reality.
I am an Irish American, and have no love for the UK in Ireland, but I still put the horrors of the Great Famine down more to incompetence then malice. Comparing it to the Terror Famine in the Ukraine under Stalin is overstating it a bit.
At the risk of repeating myself, it's more complicated.
The Protestants in Ireland were a mix of imported and conversion, with several sects. In the "south" the mainstream Anglican Church of Ireland predominated, initially as a local version of the Church of England but it liberalised notably compared to the latter.
In what we call North-East Ulster (the "six counties") there were more Methodists and Presbyterians in the Scottish mould.
This is probably a good time to point out that the mapping of Catholic/Protestant to Nationalist/Unionist is at best an inexact fit; many leaders of the historical revolutionary struggle for Irish independence were protestants. For example Wolfe Tone, Henry Joy McCracken, Lord Edward Fitzgerald, Archibald Hamilton Rowan, Valentine Lawless, James Napper Tandy and many more. In the '98 most of the leaders were Anglicans or Presbyterians.
A half-century later you had Thomas Davis, John Mitchel and William Smith O'Brien, whose "Young Ireland" movement was heavily protestant and often in conflict with Parnell. Parnell really initiated the identification of Ireland with Catholicism.
Later again you have Butt, Gray, Harrison, Jordan, McDonald, Plunkett and more. Around that time (late C19) you also saw the splitting of the Orange Order into two factions; the established Orange Order was effectively part of the Ulster Unionist Party and was aligned with the interests of landlords and employers (very much against the revolutionary spirit). As an aside, one thing that scared the bejeebus out of the NI establishment in the '30s was the development of a socialist movement that crossed sectarian lines. Unfortunately it fizzled out.
The Gaelic Revival of the late C19/early C20 period was heavily influenced by protestants; the first that comes to mind is, of course, Wilde the elder. But there were many others, Stokes, Ferguson, Æ, Yeats, Lady Gregory, O'Casey, Alice Milligan, Synge et cetera.
The opposition to Home Rule in NEU was as much economic as sectarian; a lot of the wealthy and powerful felt that their wealth and position were endangered by such a move. The parallels with Brexit are striking to those who've studied history; sectarian tensions whipped up to create a mass movement in the service of a small metropolitan economic elite.
BTW while there was a degree of "ethnic cleansing" in the south after independence most of the protestants in the cities were untouched and continued, for many years, to run parts of the civil service and serve in the Senate.
But I'm in danger of heading into lecture mode so I'll stop.
Thank you for your patience.
