Gilbert Munro, son of James Turnbull, hotelkeeper, and his wife Elizabeth, née Munro, was educated privately at Fleetwood, Lancashire, England. He worked briefly for the Fleetwood Chronicle. Then, 'Turnball trained as an architect and building surveyor, working in these professions in the United States, Canada, Mexico and the South Seas before joining the Papuan Civil Service in 1914. His work has appeared in the Bulletin, Sydney Mail, Australasian, Women's Mirror, Queenslander and other journals.' (Mackaness, George. Editor's note, Australian Short Stories (1928) p.316).
Frequently using the pseudonym 'Tauwarra' (Motu for 'fighting-man'), Turnbull published in Australian journals over 150 anecdotal paragraphs, numerous articles and at least 90 short stories. Three of his novels were serialized: Disenchantment (1932), Paradise Plumes (1934) and Mountains of the Moon (1935). A fourth novel, Portrait of a Savage (Sydney, 1943), created arguably 'the most complex character in colonial fiction before World War II'. Portrait of a Savage was rejected by eight English and three Australian publishers as 'unclean' before it was accpeted by the Currawong Publishing Company. In a preface to the book, Turnbull's editor - who signed his name as 'L.L.W.' - said that he was 'proud to bring before the Australian public this "unclean" book, not only as an absorbing work of fiction but also as a brilliant exposition of nearly all the significant facts that may be of great use to the future administrators of Papua.'
Turnbull retired from his work as government architect in Papua New Guinea to Urunga, New South Wales, in 1934. He died at Bellingen of respiratory disease and was buried in the Anglican section of the local cemetery. His wife, Jean Doris, née Winn (whom he had married on 31 August 1921 in the Presbyterian manse at Armidale, New South Wales), and daughter survived him. His unfinished novel Maraguna was completed by his biographer, Lewis Lett, but never published.
[Source for much of the biography: Helga M. Griffin, 'Turnbull, Gilbert Munro (1890 - 1938)', Australian Dictionary of Biography, Volume 12, Melbourne University Press, 1990, pp 287-288. http://www.adb.online.anu.edu.au/biogs/A120323b.htm]