The main aim of this thesis is to consider R.S. Thomas's struggle with identity during the early years of his career, primarily from birth up until his move to the parish of Aberdaron in 1967. It is an analysis both of the poet's personal life and his public, national role as a poet, examining the tensions present between his numerous, conflicting identities. The discussion is separated into three main chapters. The introductory passage takes into consideration the various ways R.S. Thomas is constructed by his critics and by the media, concentrating in particular on the varying responses to his death in 2000. Chapter 1 then moves on to discuss notions of the uncanny, as proposed by Sigmund Freud and the critic Nicholas Royle, as a means of exploring Thomas's feelings of alienation and displacement throughout childhood and early adult life. Chapter 2 is a comparative study of R.S. Thomas and the Scots vernacular poet Hugh MacDiarmid, which looks at how MacDiarmid provides for Thomas a model of Celtic regeneration, enabling Thomas to relocate himself in a cultural context, and also to explore the cultural and linguistic tensions he feels within Wales, as an English-language poet. Chapter 3 then attempts to relate the uncanny to issues of post-colonial theory, using the work of Homi K. Bhabha and David Punter as a means of providing a more theoretical basis in the form of the unhomely, and to show how Thomas's political poetry presents Wales as a terrifying, and often unreal territory within which the poet evidently felt both disorientated and displaced. This study concludes by considering various notions of personal, cultural and spiritual unity as they are presented in Thomas's work, and how ultimately, Thomas struggled to counteract the alienating forces of the uncanny and the unhomely, and to strive for a spiritual unity within himself.