There is a long tradition of Anglophobia within Irish nationalism. Much of this was grounded in the hostility felt by the largely Catholic Irish for the Anglo-Irish people, which was mainly Anglican. In Ireland before the Great Famine, anti-English hostility was deep-seated and was manifested in increased anti-English hostility organised by United Irishmen. In post-famine Ireland, anti-English hostility was adopted into the philosophy and foundation of the Irish nationalist movement. At the turn of the 20th century, the Celtic Revival movement associated the search for a cultural and national identity with an increasing anti-colonial and anti-English sentiment. Anti-English themes manifested in national organisations seen as promoting native Irish values, with the emergence of groups like Sinn Féin. One popular nationalist slogan was "England's difficulty is Ireland's opportunity", and the well-known anti-World-War-I song "Who is Ireland's Enemy?" used past events to conclude that it was England, and furthermore that Irish people ought to "pay those devils back".