Turner spent a month exploring Italy south of Rome, especially Naples and its environs, in October and November 1819, filling three small sketchbooks ('Gandolfo to Naples', 'Pompeii, Amalfi, Sorrento and Herculaneum' and 'Naples, Paestum and Rome': Tate Britain, Turner Bequest CLXXXIV, CLXXXV and CLXXXVI) and one large ('Naples: Rome. C[olour] Studies; TB CLXXXVII). Of these drawings Sir John Soane's son, John junior, wrote to his father on 15 November that 'Turner is in the neighbourhood of Naples making rough pencil sketches to the astonishment of the Fashionables, who wonder of what use these rough draughts can be - simple souls!' (Finberg, op. cit., p. 262).
The present watercolour is based directly on one of the large studies, finished in watercolour (TB CLXXXVII-13; Powell, op. cit., pl. 15, illustrated in colour), the main differences being the addition of the figures and still-life details in the foreground. Much the same view appears in another of the large sketches, in this case only partly coloured over the underlying pencil drawing (TB CLXXXVII-18, illustrated Powell, op. cit., pl. 14, in colour.)
This is one of seven finished watercolours of Italian subjects painted for Turner's great patron Walter Fawkes after his return to England. All but one are dated 1820 or 1821 (Wilton, op. cit., p. 383, nos. 718-24); they show scenes in Venice, Rome and Naples. Turner had already painted three views of Vesuvius, two in eruption, one in repose, in or about 1817 and probably from sketches by James Hakewell (Wilton, op. cit., p. 381, nos. 697-99, illustrated p. 381 and in colour pl. 145.
Some confusion exists as to which views of Vesuvius were exhibited by the publisher W.B. Cooke in 1822. As well as works by Turner there were also drawings by Reynolds, Gainsborough, Wilson, Lawrence, Cozens and Girtin as well as by 'ancient masters' such as Michelangelo, Raphael, Claude and Rembrandt. Most of the works actually belonged to Cooke, such as the Turners done for Cooke's publications, so it seems unlikely that a work belonging to Fawkes would have been included. The identification of the present watercolour with that shown, made by Finberg (op. cit., p.483, no. 261) and Wilton (loc. cit.) has been corrected by Powell (op. cit., pp. 81, 204, n. 53) and Wilton himself (Turner in his Time, London and New York, 1987, p. 165). The 1839 exhibition in Leeds did, however, include 43 watercolours from the Fawkes collection.