Matthew Forster was a barrister. He married Amy Leslie Worth, and had a daughter, Yvonne Isabella (b. 21 October 1877), who married Henry Dyson. They had two daughters, Maude Elizabeth and Nina Dorothy.
Forster was a barrister in the firm of Frere, Forster and Frere, solicitors to the Arts Club.
JW was friendly with the Forster family (#07889, #08778), who lived at 37 Ennismore Gardens in Knightsbridge. Forster's name was included in a list by JW that may have been for the private view of his 1874 Pall Mall exhibition or an 1876 subscription list for his envisaged set of Venice etchings (#12714). In 1878 JW offered Forster a proof of Richard Josey's etching of Arrangement in Grey and Black, No. 2: Portrait of Thomas Carlyle (YMSM 137) (#11680).
In a letter to his sister-in-law dated 16 December 1881 JW mentioned that he was working on a portrait of Forster's wife (#06695). Her portrait was still in his Tite Street studio in 1884 when the artists Walter Sickert and J. E. Blanche saw it there. It was apparently a 'black on black' portrait, but nothing further is known of it (Portrait of Mrs Forster (YMSM 234)). About 1881/1884 Whistler drew a portrait of Forster's young daughter (Portrait of Miss Yvonne Forster (M.838)).
Venn, J. A. (ed.), Alumni Cantabrigienses 1752-1900, Cambridge University Press, 1940-1954; Young, Andrew McLaren, Margaret F. MacDonald, Robin Spencer and Hamish Miles, The Paintings of James McNeill Whistler, New Haven and London, 1980; MacDonald, Margaret F., James McNeill Whistler. Drawings, Pastels and Watercolours. A Catalogue Raisonné, New Haven and London, 1995.