This thesis examines the previously unrecognised importance of apotheosis as both a concept and a trope in Blake's literary and artistic works. Apotheosis can be defined as the transformation ofa human into a god or demi-god, most often figured posthumously as the ascension of the hero's soul to the stars in reward for services to the nation. The term also refers to the deification of powerful rulers whilst living. In both forms, apotheosis aestheticises ideology and authority through spectacle, imbuing both its representation and critique with political significance. The motif of apotheosis recurs throughout Blake's poetry and painting, and particularly informs his distinctive use of star imagery. I trace how Blake's engagement with the concept and its representation reflects both his conception of the political and his complex relationship to Enlightenment and radical thought. He shared with rational Protestants, Deists, and freethinkers a scepticism towards mythologised political authority, expressed in their shared investment in Euhemerism - a rational approach to myth, religion, and by implication state authority, which traces divinities back to deified mortals and state religions. Blake, however, retained an investment in mythopoesis and a radical scepticism towards rational individualism. The thesis places Blake in the context ofa wide range ofcontemporary historical materials. I examine his use ofthe apotheosis trope against the backdrop of the American and French Revolutions, in his juvenilia and The French Revolution (1791). I then examine the role ofapotheosis in the Lambeth prophecies, in the context of radicalism and state repression in the 1790s. Blake painted 'grand apotheoses' ofNelson and Pitt which he exhibited in 1809, and I explore the complex way he uses the motif satirically to undermine official models of heroism. Blake's treatment ofapotheosis went through a number ofdifferent permutations in which the balance between a negative critique and a positive transformation ofthe trope into images of resurrection and social renewal achieves a varying equilibrium. I conclude with an extended examination ofJerusalem (c.1804-20), exploring its emphatic focus on the energies ofthe resurrected body politic, demonstrating how Blake used the trope of apotheosis to envisage the potential for a transformation ofpolitical society.