Painter, muralist and illustrator John Henry Amshewitz was born into a Jewish family in Ramsgate, England on 19 December 1882 (his father, Asher Amschejewitz, an Orthodox rabbi and scholar, born in Vilna, had come to the Montefiore College in Ramsgate in 1867 as a scholar in residence). Amshewitz won an art scholarship to study at the Royal Academy School from 1902-07, under the direction of John Singer Sargent, Sir George Clausen and Solomon J. Solomon. While still a student, he won several important civic commissions including four murals for the Centenary Memorial at the Liverpool City Hall in 1907, and a mural for the Royal Exchange in London in 1910. His friendship with Whitechapel Boy Isaac Rosenberg led to a portrait of the young poet-painter in 1909. He also illustrated a number of works for the Jewish writer Israel Zangwill, including Ghetto Comedies (1907), and later illustrated a Haggadah (1930). He was elected a member of the Royal Society of British Artists in 1914.

In 1916, after being rejected for military service (owing to an injury incurred during the creation of the Liverpool murals), he accepted a theatrical role in a production for a six-month tour of South Africa, staying on for six years. He held his first exhibition in South Africa in 1916, followed by many others, and was elected member of the South African Society of Artists in 1917. In 1918, he married Sarah Briana Judes in Johannesburg (after his death, she went on to publish The Paintings of JH Amshewitz (London, 1951)). He founded the Johannesburg Sketch Club the same year and, as President, served as a mentor and critic to other Johannesburg artists, also working as cartoonist for the Rand Daily Mail and Sunday Times. He returned to England in 1922, becoming friendly with Walter Sickert, and carried out a mural commission for South Africa House. He returned to his Johannesburg studio in 1936, where he was commissioned to create a mural for Pretoria City Hall in 1938. He died in South Africa in 1942. His work is represented in the South Africa National Art Gallery in Cape Town and the Johannesburg Art Gallery, as well as the Metropolitan Museum, New York, and the National Portrait Gallery and Victoria and Albert Museum in London.