The Royal Irish Constabulary was the police force in Ireland from 1822 until 1922, when all of the country was part of the United Kingdom. A separate civic police force, the unarmed Dublin Metropolitan Police (DMP), patrolled the capital and parts of County Wicklow, while the cities of Derry and Belfast, originally with their own police forces, later had special divisions within the RIC. For most of its history, the ethnic and religious makeup of the RIC broadly matched that of the Irish population, although Anglo-Irish Protestants were overrepresented among its senior officers.

Irish nationalism is a nationalist political movement which, in its broadest sense, asserts that the people of Ireland should govern Ireland as a sovereign state. Since the mid-19th century, Irish nationalism has largely taken the form of cultural nationalism based on the principles of national self-determination and popular sovereignty. Irish nationalists during the 18th, 19th, and 20th centuries such as the United Irishmen in the 1790s, Young Irelanders in the 1840s, the Fenian Brotherhood during the 1880s, Fianna Fáil in the 1920s, and Sinn Féin styled themselves in various ways after French left-wing radicalism and republicanism. Irish nationalism celebrates the culture of Ireland, especially the Irish language, literature, music, and sports. It grew more potent during the period in which all of Ireland was part of the United Kingdom, which led to most of the island gaining independence from the UK in 1922.