Who rules?

Because of the references to the English parliament and Irish politicians having to go over to ask permission to play ball games in Ulysses it made me check out who was running the country at the time the book was written and it was the British who ruled in Ireland until 1921, when the Anglo-Irish Treaty was signed and partition was a result. It’s useful to know what sort of background the book was being written against and it explains the references to Irish nationalist groups some characters make, particularly in the pub.