There were numerous reasons why the people of southern Ireland wanted to be independent and not be under the British crown. Probably the main reason is religious one, as the British were predominantly Protestant, while the Irish were Catholic. There were lot of tensions based on the religion, and there were constant clashes and tensions between the two different religious groups. Not willing to be under the control of an empire that had different religion, and one that they despised, the Irish demanded independence, and eventually they managed to get it.