James Priestley was senior surgeon at the Mayo Clinic. He was born on 7 April 1903 in Des Moines, Iowa. He was the son of Crayke S Priestley and Lilian Priestley, and a descendant of the Rev Joseph Priestley FRS (1733-1804), friend of Benjamin Franklin and Joseph Banks, a notable theologian and the discoverer of 'dephlogisticated air' (oxygen). Joseph emigrated to Philadelphia in 1796, where he became a friend of Adams and Jefferson, and founded the First Unitarian Church. James was the fifth member of his family to be educated at the University of Pennsylvania and was an intern at the University of Pennsylvania Hospital from 1926 to 1928. He went to Rochester as a fellow in surgery at the Mayo Graduate School of Medicine, where he received the degree of master of science in experimental surgery, followed by the DPhil in surgery the following year. He was appointed to the staff of the Mayo Clinic in 1933, and in 1934 became the head of a section of surgery, a post he occupied for the next 34 years. He was commissioned into the Medical Corps of the US Army in 1943, where he won the bronze star and the oak leaf cluster for gallantry. He became senior surgeon of the Mayo Clinic in 1963. He retired in 1968, having been President of the central surgical association, and special consultant on the clinical research training committee of the National Institute of General Medical Sciences, National Institutes of Health. In 1965, 70 of his former first assistants in surgery formed the Priestley Society, which now comprises more than 600 members, mostly Mayo Clinic alumni, from all over the world. Priestley was the author of several surgical textbooks. He married Klea Palica in 1930. They had three daughters (Barbara Ann, Martha and Judith) and one son (James Priestley III). There are 12 grandchildren. He died on 9 February 1979 of a heart attack whilst on vacation in Florida.