The title of this picture indicates that Whistler's main purpose was to capture the effect of twilight through harmonies of colour. However, the subtitle, 'Valparaiso', also gives a clue to the subject: the Spanish bombardment of Chile's principal harbour in March 1866.
Responding to the Spanish occupation of the Peruvian-owned Chincha Islands in 1864, the South American countries of Chile, Bolivia and Ecuador formed an alliance with Peru against Spain. In February 1866 Whistler left London for South America, in order to assist the Chilean cause. When he arrived in Chile on 12 March a squadron of six Spanish ships was blockading the country's main harbour, Valparaiso. In order to protect their own nationals and act as a neutral, peacekeeping force, the British, American and French governments had sent out their own fleets, who were also present. On 27 March the Spanish announced their intention to bombard the city. Although outraged by this act of aggression, the British, American and French fleets had no option but to withdraw. Whistler's picture almost certainly records the beginning of their withdrawal, on the evening of 30 March. The following day the Spanish bombarded the city, by which time Whistler had fled to the hills on horseback.
Whistler painted three other canvases in Valparaiso, all depicting the prelude or aftermath to the hostilities. According to Eddy, he completed this picture 'at a single sitting, having prepared his colours in advance' (Arthur J. Eddy, Recollections & Impressions of James A. McNeill Whistler, Philadelphia 1903, p.23). From this, we can gather that he was working from memory and that the overall effect was more important than accuracy of detail. We know from contemporary accounts that the Americans sent one iron-clad turreted ship and five steamers, and that the French and British fleets included frigates and gunboats. Despite this, Whistler has depicted mainly sailing ships, some of which have started to unfurl their sails, ready to move towards the open sea. The only clearly visible flag is the French tricolour in the centre of the composition, silhouetted against the gathering violet and purple clouds. Comparisons have been drawn with Manet's early marine views of 1864-5, and especially his depiction of the Battle of the Kearsarge and the Alabama (1864, Philadelphia Museum of Art).
When it was exhibited at the French Gallery in London in 1867 the picture was well received. The critic writing for the Athenaeum commented on the way in which Whistler had given 'an aspect of sleepy motion to the vessels, and…conveyed to the spectator the rolling, seemingly breathing, surface of the sea with a power that is magical' ('The Winter Exhibition at the French Gallery', Athenaeum No.2045, 5 January 1867, pp.22-3).
Richard Dorment and Margaret F. MacDonald, James McNeill Whistler, exhibition catalogue, Tate Gallery, London 1994, pp.117-8, no.44, reproduced in colour p.118.
Andrew McLaren Young, Margaret F. MacDonald, Robin Spencer with the assistance of Hamish Miles, The Paintings of James MacNeill Whistler, New Haven and London, 1980, no. 73, reproduced in colour plate 57.