Manton was a successful artist, specialising in portraits, genre and religious subjects. He was also an illustrator working for several magazines, including Black & White, and illustrating numerous books. He was briefly married to Blanche Lucretia Cottle (qv), before remarrying in 1889. He exhibited 39 paintings at the Royal Academy and 19 at the Royal Society of British Artists of which he was a member from 1899. He usually signed his work ‘G Grenville Manton’.