The revival of Irish literature in the nineteenth century involved looking backwards as much as forward. Modernists such as Joyce, Beckett and Flann O'Brien were seen as internationlists, opposed to the Celtic revival which was a strongly nationalist, artistically traditional movement. Behind the return to the Irish past was the longing for a distinctly Irish future, freed of English domination. The English language and the Church of England were viewed as the cultural heritage of foreign invaders. The search for political independence was accompanied by a desire for cultural authenticity, rooted in Celtic tradition rather than either European or English traditions.
While the Catholic Church was a crucial part of Irish identity and had done much to bring help and education to Ireland during the long period of English oppression, many of the thinkers of the Celtic Twilight still saw Roman Catholicism as having been imported to their island and supplanting a more authentic Irish Christianity, with its own traditions including its own liturgy, date for Easter, different types of tonsure, and what were called mitred abbesses (female abbesses with great power who sat on important church councils). The Synod of Whitby of 664 made the English Roman Catholic church conform to Roman practices rather than the Celtic traditions of Iona. Many later Irish nationalists saw a return to Celtic pre-Whitby traditions as more authentically Irish. St. Patrick, known for bringing Christianity to Ireland and driving snakes out of it, was admired as a national figure.
Revival of the Irish language and pre-Christian traditions was also seen as an important element of cultural identity. Lady Gregory and William Butler Yeats were among the important figures in bringing such figures as Sweeney and Cuchulain back into the imaginative landscape as founding figures of Irish culture. Often the versions of these figures were somewhat romanticized, a creation of the "Celtic twilight" heavily influenced by Romanticism. Often this meant that the Celtic myths were assimilated into a sort of generic medievalism, and the heroes made more noble and chivalric than would have been historically the case.