Fundamental to the development of the aesthetic of 'picturesque neo-classicism', of which Thomas Hope was a proponent, are the engravings of Piranesi and in particular his heroic series of Roman public buildings (D. Watkin, Thomas Hope and the Neo-Classical Idea, London, 1968, pp. 128-129). Hope regarded Piranesi as of the first importance in his approach to art and design. In a letter to Matthew Boulton of 1805, he stated that he 'endeavoured to make myself master of the spirit [Hope's italics] of the Antique.' and that any student, rather than merely copying Hope's designs 'would do better still by applying at once to the fountain-head, to those sources of beauty which lay open to every body: I mean the most approved books on ancient art: Sir Wm. Hamilton's Vases, Winckelman, Piranesi, Stuart's Athens, Ionian Antiquities &c. &c. &c.' (ibid., p. 198).