Henry Matthew Brock was born in Cambridge on 11 July 1875, studied at Cambridge School of Art and became an illustrator and cartoonist, sharing a studio with his elder brother C. E. Brock. He contributed to Punch and worked in book illustration and advertising. He also exhibited his drawings and watercolours, becoming a member of the Royal Institute of Painters in Watercolours in 1907. From the 1930s on he worked in comics, drawing "The Mystery of Study 13" for Sparkler (1937), "Breed of the Brudenells" for Knockout (1949), "The Loring Mystery" in Thriller Picture Library #25 (1952), and an adaptation of Lorna Doone for Princess (1960). He died in 1960, aged 85. The University of Reading has an H. M. Brock Collection, which is made up of some 2000 books in which Brock's work was published, many periodical volumes and parts, ephemera such as cigarette cards, and pictures, including over 70 original drawings.
- Alan Clark, Dictionary of British Comic Artists, Writers and Editors, The British Library, 1998, p. 28
- H. M. Brock on the Books and Writers website
- H. M. Brock on Victorianweb
- H. M. Brock on the Cambridge Book & Print Gallery website
- The H. M. Brock Collection at the University of Reading