I approach Blake's 'Jerusalem' in the light of the two main traditions in which it is found: the Biblical prophetic tradition, and the English epic tradition. After a general introduction, setting forth the terms of reference of the thesis, and outlining my method of approach, my second chapter contains a statement identifying the texts of the poem, and a chronological review and assessment of previous criticism. In the third and fourth chapters, I discuss the poem in terms of its contexts of epic design and of Biblical prophecy. The central section of the thesis, the fifth chapter reviews some of the major eighteenth century studies of the Book of Ezekiel, which may have influenced Blake's reading of the book, and examines the extent of its similarities with 'Jerusalem' under the headings of situation, structure and stylistic features. This discussion of the poem leads to a close reading of the complete poem in the sixth chapter, showing the depth and coherence of Blake's design.