also involved in Utopian social thought in the wake of the French Revolution. The poet and painter William Blake is the most extreme example of the Romantic sensibility in Britain, epitomised by his claim 'I must create a system or be enslaved by another man's'. Blake's artistic work is also strongly influenced by Medieval illuminated books. The painters J. M. W. Turner and John Constable are also generally associated with Romanticism. Lord Byron , Percy Bysshe Shelley , Mary Shelley and John Keats constitute another phase of Romanticism in Britain. The historian Thomas Carlyle and the Pre-Raphaelite Brotherhood represent the last phase of transformation into Victorian culture. In Russia the principal exponent of Romanticism is Alexander Pushkin , though Russian composers are also given the label. Pushkin's Shakespearean drama 'Boris Godunov' (1825) was set to music by Modest Mussorgsky .