Josiah Grant Bonnin was born at Ararat, Victoria, Australia on 26 January 1909, the only son of Francis Bonnin, a general practitioner surgeon, and Ellen (nee Grant). His early education was at Ararat Grammar School where he won a scholarship to Geelong College, Victoria. He then entered Melbourne University, qualifying in 1931. His early house appointments at the Royal Melbourne Hospital were with Sir Alan Newton and Mr William Hailes and following this he spent a second year resident at Melbourne Children's Hospital and a third year at Melbourne Women's Hospital doing obstetrics and gynaecology. During this time he collected material for the MRCOG which he passed in January 1934, one month after arriving in England. In the following year he gained the FRCS which had been his primary object in coming to England. Following this he worked at St James's Hospital, Balham, with Sir William Gissane and with Constantine Lambrinudi. Here he gained his first experience of orthopaedic surgery which at that time was undeveloped in Australia. He soon realised that this subject was of particular appeal to him as he was an excellent carpenter and bone surgery suited his manual dexterity. From 1936 to 1938 he spent some time at Freiburg University and also in Vienna, studying under Bohler at the orthopaedic clinic and on his return to England was appointed senior casualty registrar at the West London Hospital. In 1940 he became surgeon in charge of the Central White Lodge Emergency Hospital at Newmarket and in 1942 joined the Royal Army Medical Corps for five years ending with the rank of Lieutenant-Colonel. He was involved in the invasion of Normandy and later became adviser in orthopaedics to South East Asia Command and also personal orthopaedic adviser to Lord Louis Mountbatten. After demobilisation he was appointed consultant orthopaedic surgeon at the Central Middlesex Hospital, London and in the following year was elected Hunterian Professor. He was the only consultant in orthopaedics at the Central Middlesex for the first 16 years and developed a full accident, fracture and casualty service at the hospital. He was a prodigious writer producing his first textbook in 1941 *A complete outline of fractures* which ran to three editions; he contributed many articles to orthopaedic journals especially on surgery in the aged. A further textbook *Injuries to the ankle* was published in 1951. He served as review editor of the *Journal of bone and joint surgery* from 1962 to 1974 and as President of the Orthopaedic Section of the Royal Society of Medicine in 1972 where he gave a paper on treatment of recurrent dislocation of the shoulder by transplantation of the tip of the coracoid process. In 1974 he retired from the hospital service but continued to devote time to medico-legal work. He married Joy Chapple in 1940 and had three sons. After his retirement he spent much time at his house in France where he returned to the country life that he had enjoyed so much as a boy. He died on 26 October 1989, aged 80.