The thesis concerns itself with the animal poetry of Ted Hughes. It traces, in a chronological structure, the development of how Hughes uses animals in his work, identifying four different phases in his writing. This is mainly done through close textural analysis. The introduction contextualises Hughes in relation to animal poetry and gives a broad overview of the four sections of the thesis. Section I examines the first three volumes of Hughes's career: The Hawk in the Rain, Lupercal and Wodwo. The issues of violence in his work, and how he uses animals poetically to imply a critique of the human realm, are addressed. This section also examines Hughes's early work for children. Section II discusses Hughes's mytho-poetic ventures of the 1970s: Crow, Prometheus on his Crag and Cave Birds. It is shown that Hughes moves away from the primitivism of the real, observable animal world and seeks to present his creatures in a mythological framework. Section III shows that from the mid-1790s Hughes was writing animal poetry of a different nature, presenting creatures in a domestic or natural environment, exploring their various relationships with man, and that this was the way his work developed throughout the 1980s. The volumes discussed are Season Songs, Moortown, Remains of Elmet, River, Flowers and Insects and Wolfwatching. Section IV examines how, in the 1990s until the end of his life, Hughes moved back to a mythological treatment of animals in his work, either in an emblematic way (as in his Laureate verse in Rain-Charm for the Duchy), or as a unifying principle (as in his analysis of the works of Shakespeare and Coleridge). This treatment is seen to culminate in the poetry of Tales from Ovid. There are some final thoughts on the animal imagery Hughes uses in Birthday Letters.