Lamb was born in Australia, the son of Sir Horace Lamb FRS, professor of mathematics at Adelaide University. When Sir Horace was appointed to the Chair of Mathematics at the Victoria University of Manchester in 1885, the family moved back to England. Henry Lamb attended Manchester Grammar School before studying medicine at Manchester University and Guy’s Hospital in London.
In 1906 Lamb abandoned medicine to study painting at Chelsea School of Art, then run by William Orpen and Augustus John. In 1907 he studied in Paris at the Académie de la Palette, where the painters Jean Metzinger, André Dunoyer de Segonzac and Henri Le Fauconnier taught. Lamb made subsequent summer trips to Brittany between 1908 and 1911. The main influence at this date is clearly Gauguin, who had also worked in Brittany. There were thirty-seven works by Gauguin in the celebrated exhibition of Post-Impressionist painting in London in 1910 and the older artist’s use of simplified forms and flat colour is apparent in Lamb’s work.
Lamb was associated with Augustus John and was a founder member of the Camden Town Group in 1911 and of the London Group in 1913, which took over from the Camden Town Group. The stated aim of the London Group was ‘to advance public awareness of contemporary visual art by holding exhibitions annually’. Its first president was Harold Gilman, one of the leading Camden Town painters. Iconic works by David Bomberg, Jacob Epstein and Mark Gertler were included in the group’s first exhibition in 1914 and in several subsequent exhibitions.