Martyn was born in London on 6 August 1935. His father, Sir Clement Price Thomas, was surgeon to King George VI, President of the BMA, the Association of Surgeons, the Royal Society of Medicine and Vice-President of the College. His mother was Dorrie Ricks. He was educated at Leighton Park and then went into the RAF medical branch to do his National Service, before going on to St Thomas's. There he won the Grainger prize in anatomy and was greatly influenced by Sharpey-Schafer and Arthur Buller. He was house surgeon to Robert Nevin and house physician to Bill Medd and Kingston. After a period as an anatomy demonstrator, he went to Hammersmith as house surgeon to Richard Franklin and Selwyn Taylor, before going on to Oxford to complete his surgical training. He was appointed consultant surgeon to the Royal Gwent Hospital in Newport in 1975, where he developed a special interest in urology and breast cancer. In 1995 he moved to Addenbrooke's Hospital, Cambridge, to teach anatomy and be a consultant to their breast unit. He was a talented painter and sculptor, and a member of the Chelsea Arts Club, as well as a keen sailor and golfer. In 1962 he married Deirdre Irene McMaster. They had three daughters, Emma, Kate and Clem, who inherited his artistic talents. He died on 6 June 2000 from a sarcoma of the oesophagus.