In independent Ireland, civil war threat receded in 1927 when Eamon de Valera led his anti-Treaty party, Fianna Fáil, into the Dáil, the lower, elected house of the Free State’s bicameral parliament. The pro-Treaty parties were Fine Gael and the Labour Party. Various short-lived parties challenged the supremacy of the Big Three over the decades. There was investment in infrastructure (electricity, transport, agriculture, food processing) and native industry flourished from the 1930s to the 1950s behind high tariff walls, but unemployment and emigration persisted. Health care was improved from the mid-1940s. The Catholic Church exercised huge power.

In Northern Ireland unionists’ majority led to systematic discrimination against Catholics (assumed nationalist) in elections, employment and housing. Economically, apart from the Second World War, Northern Ireland experienced decline but it shared in the social benefits of postwar Britain.

The 1960s brought more questioning of authority of all kinds, all over the island. In independent Ireland, new-found prosperity removed the safety-valve of emigration and free secondary education improved opportunities. Living standards rose. In the North, Catholic dissatisfaction was expressed in civil rights demonstrations which outraged unionists, and the British army was called in to maintain order.