Professor Peter Williams was an outstanding anatomist who was known and respected world-wide for the editing and revision of *Gray's Anatomy*. He was born on 11 November 1926 at Caerleon in Gwent, the elder son of Jack Williams, a Welsh education and child-welfare officer. His father, who held strong left-wing political views, was a renowned orator and contested the North Devon seat for Labour (subsequently won by Jeremy Thorpe). His mother, who strongly supported him in his chosen career, was a district nurse and midwife. Peter Williams was educated at the Jones West Monmouth School in Pontypool, and subsequently won a state scholarship to St Catherine's College, Cambridge, in 1944, where he was awarded first-class honours in both parts of the natural science tripos. He also won the St Catherine's scholarship in anatomy and the Marmaduke Shield university scholarship in anatomy. His tutor was Dr D V Davies, a formidable figure well-known to that generation, who described him as the best student he had ever had, and Davies and Peter Williams were known by their contemporaries as 'the only persons to know every word in Gray'. In 1947 he went to Guy's Hospital Medical School as a clinical student, where he won the Treasurer's gold medal in 1950. After junior appointments at Guy's, he did his National Service in the RAMC at BMH Wuppertal in Germany, and then returned to Guy's, where he became successively research fellow, lecturer, senior lecturer and reader in anatomy. In 1970 he was appointed Professor of Anatomy at London University, a position he held for the next ten years. He was a distinguished teacher and researcher in anatomy, and besides numerous papers on neuroscience he wrote *Basic human embryology* (which ran to three editions) in 1966 and *Functional neuroanatomy of man* in 1975. His research into the functions of the neuron and its myelin sheath gained him a DSc from London University in 1970. It is, however, with the modernisation of *Gray's Anatomy* that his name is inseparably linked, and he 'retired' in 1980 in order to devote himself to this task. In 1954 he had been appointed indexer for the centenary edition (32nd) of Gray's by Professor T B Johnson, and he became expert adviser to Professor D V Davies for the 34th edition. Davies, who resisted change in the book, died prematurely in 1968, after which Williams became joint editor with Roger Warwick for the 35th edition. This was an opportunity to introduce radical changes in format with an altered text and bibliography, and over 600 new diagrams, many drawn by Williams himself. He became senior editor for the next two editions, and in 1989 chairman of the editorial board for the 38th edition, in which some 150 specialist contributors participated. His life's endeavour, as he himself said, was to transform the study of anatomy from a static, descriptive exercise into a vibrant, dynamic and experimental natural science, interlocked with other disciplines, and in this he certainly succeeded. He had a fiery personality, and would never admit to retirement in the usual sense of the word. His outside interests included gardening, astronomy and cricket, which he followed enthusiastically. He married Irene Holland in 1954 and they had one son, Ross, and a daughter, Lyn. His younger brother, Michael, is emeritus professor of anatomy at Sheffield University. He died aged 67 on 5 October 1994 following a heart attack, some six years after a successful coronary bypass operation for angina.