Hugh Evelyn Lockhart-Mummery was born in London on 28 April 1918, the son of John Percy Lockhart-Mummery FRCS (1875-1957) and his wife Elizabeth, née Gibbons. He was educated at Sandroyd Preparatory School, Stowe and Trinity College, Cambridge, where he was an exhibitioner in 1938 and senior scholar in 1939. During his time as an undergraduate in the years before the war he served in the cavalry division of the University Officers Training Corps. At the outbreak of war he started clinical studies at Westminster Hospital having been awarded an entrance scholarship and qualified in 1942. He passed the Fellowship in the following year after completing house officer appointments and was then commissioned into the medical branch of the Royal Air Force serving as surgical specialist with the rank of Squadron Leader in the Far East and in the West Indies. He was demobilised in 1946 and returned to Westminster Hospital for higher surgical training under Sir Stanford Cade before being appointed resident surgical officer at St Mark's Hospital in 1950 and consultant resident surgeon in the following year, a post which had been held by his father and which he held until 1978. For short periods he was also consultant surgeon to the Italian Hospital in London (1954¬59), St John's Hospital in Lewisham (1955-57) and the Memorial Hospital in Woolwich (1955-60). In 1960 he became consultant surgeon to St Thomas's Hospital, the first surgeon in 60 years to be appointed to the consultant staff who had not trained at the hospital. He continued serving on the staff until 1982; although appointed as consultant general surgeon, his work there was largely colo-rectal. He was also consultant surgeon to the King Edward VII Hospital for Officers and chairman of its medical committee, and in addition served as Chairman of the Medical Sickness Annuity and Life Assurance Society. He was elected President of the Section of Proctology of the Royal Society of Medicine in 1966. Throughout his professional life he continued to undertake clinical research. In 1952 in conjunction with Dr Cuthbert Dukes he reviewed the pathology and treatment of malignant colonic and rectal polyps and concluded that if a free margin of healthy tissue was, present after polypectomy the bowel could be preserved provided the tumour was not of high grade malignancy. He continued in conjunction with Dr H J R Bussey to maintain the register of families afflicted with polyposis colic, which had been started by his father during his service on the staff of St Mark's Hospital. Always interested in preservation of sphincter control he pioneered in conjunction with Mr R J Heald the introduction of stapling devices emphasising the importance of skilled low pelvic dissection. His main research interest was inflammatory bowel disease which was the subject of his MD thesis in 1956. He recognised that some cases did not fit the clinical and pathological patterns of ulcerative colitis and in conjunction with B C Morson published an influential paper in 1960 distinguishing Crohn's disease of the colon from ulcerative colitis and emphasising the significance of the anal lesions in Crohn's disease. He was appointed Surgeon to Her Majesty's household in 1969, Surgeon to the Queen in 1974 and Serjeant-Surgeon from 1975 to 1983. Lyn Lockhart-Mummery was always approachable and courteous. He was a sound diagnostician emphasising the importance of a detailed history and thorough examination. He was a skilled operator and much loved by all his patients on account of his kind temperament and willingness to spend time with them explaining in detail the problems of their illness. His relaxations were music, golf and fishing. He retired to Hannington, near Basingstoke, and died on 24 June 1988 after a long illness borne with great courage. A memorial meeting was held in his honour at the Royal Society of Medicine in February 1990 under the auspices of the Section of Colo-proctology. He married first Elizabeth Jean Crerar who died suddenly in 1981 and secondly Jean Elizabeth Hoare, who survives him, together with a son from his first marriage, Christopher Lockhart-Mummery QC.