“The Wanderings of Oisin” was published in 1889 and is one of W.B Yeats’ earliest poems and is the main focus for this essay. The poem depicts the duality of Irish identity and the transition from one system of belief to another. This essay will demonstrate that W.B Yeats uses Celtic and Catholic mythology in “The Wanderings of Oisin” in order to reflect his contemporary Ireland. The essay begins with a deifintion and a discussion about the words 'myth' and 'mythical method'. The second part of the essay describes the depiction of Celtic and Catholic mythology in “The Wanderings of Oisin” and the connection to late nineteenth century Ireland. The first section presents information on Irish nineteenth-century history and the second section focuses on five parallels to Yeats' contemporary society: The vitality of Celtic mythological beings, the depiction of Oisin as mediator, the sense of loss regarding Irish culture, the juxtaposition of Celtic and Catholic and the ambivalence that follows in a society where two conflicting mythologies coexist and compete. The main body of arguments discusses these parallels between Yeats’ portrayal of Celtic mythology and nineteenth century Ireland and shows that "The Wanderings of Oisin" reflects Yeats' contemporary Irish society.