Solomon was the youngest of eight children in an orthodox Jewish family in the East End of London; his brother Abraham and sister Rebecca were also artists. After early training at Leigh's and Cary's academies, he entered the Royal Academy Schools in 1855 and there formed a sketching club with three contemporaries - Henry Holiday, Albert Moore and Marcus Stone. A lively, precocious youth, he met Rossetti and Burne-Jones about 1858, by which time he was already producing highly finished drawings and watercolors in the Pre-Raphaelite style, generally illustrative of Hebraic history and ritual; between him and Burne-Jones there was a good deal of mutual influence. He exhibited at the Royal Academy 1858-1872, and was a regular contributor to the Dudley Gallery from 1865. During the 1860s he was involved in the revival of book illustration, did decorative work for William Morris and William Burges, and - fatally for someone of his temperament - became closely associated with a group of men formulating the ideals of the Aesthetic Movement, notably Swinburne and Pater. Under their influence he turned to classical themes, and between 1866 and 1870 he paid three visits to Italy, where he was much influenced by Leonardo and his school. In Rome in 1869 he wrote the prose poem A Vision of Love Revealed in Sleep on the platonic theme of the fulfillment of the soul through earthly love; this was published in 1871 and warmly reviewed by Swinburne and J.A. Symonds.
In February 1873 Solomon's career collapsed when he was arrested and convicted for homosexual offences. He never regained his position in respectable society, or apparently wished to, preferring to live the life of a vagabond and alcoholic, based (from 1884) at St. Gile's Workhouse, Seven Dials. However, he continued to work, producing large numbers of watercolors and chalk drawings with symbolist themes. He died at St. Gile's and is buried in the Jewish Cemetery, Willesden. [The Last Romantics: The Romantic Tradition in British Art, ed. John Christian (London, 1989) 82.]