Topic summary
British dominion

Extracted from the Wikipedia article Dominion.
Irish Free State / Ireland
The Irish Free State (Ireland from 1937) was a British Dominion between 1922 and 1949. As established by the Irish Free State Constitution Act 1922 of the United Kingdom Parliament on 6 December 1922, the new state—which had Dominion status in the likeness of that enjoyed by Canada within the British Commonwealth of Nations—comprised the whole of Ireland. However, provision was made in the act for the Parliament of Northern Ireland to opt out of inclusion in the Irish Free State, which—as had been widely expected at the time—it duly did one day after the creation of the new state, on 7 December 1922.