Born on 28 August 1868, the eldest son of D W Jones JP of Aberdare, he was educated at a private school, at Perry's School, Cardiff, and St Bartholomew's Hospital. He qualified in 1890, and passed the Fellowship examination before his twenty-fifth birthday, the earliest permissible age. He held resident posts at St Bartholomew's and was house surgeon to Sir Thomas Smith. Llewelyn Jones decided to settle in his home town, Aberdare, South Wales, and returned there in 1894. In co-operation with the Powell Duffryn Company and the miners, Jones was one of the founder surgeons of the Aberdare General Hospital. He was medical officer to the Post Office for many years and a medical referee under the Workmen's Compensation Acts. Jones was a fearless and skillful operator. His leisure hours were spent in fishing and shooting, but this active life was curtailed when he began to go blind, and he was forced to retire in 1944. He was tall and of distinguished appearance with a grave, courteous manner. In 1906 he married Ethel, second daughter of Brunel White of Carmarthen, and they had two sons: the elder an ophthalmic surgeon, the other a solicitor and town clerk of Durham. Martin Llewelyn Jones had been a Fellow for sixty years when he died on 23 March 1954, aged 85.