Born in Paris on 24 June 1874. His father, a lawyer, died when Pierre was seven years old, leaving a widow and six children. He was educated at the Lycée Monge and the Lycée Condorcet, at Heidelberg, and at the University of Paris, where he passed every examination with honours. In 1898 he began his internship, serving under Edouard Quénu, Reclus, Lannelongue, and Guyon. At the Faculty of Medicine he served as demonstrator to Faraboeuf, assistant in anatomy 1899, and prosector 1901. In 1902 he graduated MD with a thesis on the semiology of cancer of the pelvic colon, and won the gold medal. He proceeded agrégé in surgery 1904, and chirurgien des hôpitaux 1905. From 1901 to 1912 he acted as assistant to Edouard Quénu, with whom he did considerable research, including a study of anastomosis of the ureters into the large intestine. He always remained interested in genitourinary surgery. Quénu turned his interest primarily to the surgical pathology of the large intestine. In his thesis Duval described for the first time the mobilization of fixed segments of the large intestine by colo-parietal décollement, a revolutionary technique which was universally adopted. In 1913 he made a remarkable report on surgery of the pelvic colon to the Congrès de Chirurgie. Through this period Duval had worked on a wide variety of surgical problems. With Quénu he published the first French account of splenectomy in Banti's disease; and he contributed sections on genito-urinary surgery and on diseases of the intestine, rectum, and peritoneum to well-known textbooks. In 1912 Duval became head of the surgical clinic at Bicêtre, but before he could make his mark he was called to the army as aide-major in the ambulance service of the 10th Army. He served in the withdrawal from Belgium, autumn 1914, and the first battle of the Marne. Then he was posted to Fougères at the base, and soon given surgical direction of the 10th Region with control of 14,000 beds. He proved himself a brilliant administrator. In 1916 he returned to active service as médecin-major 1st class, in charge of Ambulance Corps 21 at Bray-sur-Somme and at Noyon. In 1917 he assumed the surgical control of the Army of Flanders with headquarters at Zuydcoote, halfway between the casualty clearing stations and the base hospitals of Amiens and Abbeville. Later he went to Malmaison, was consulting surgeon with the Army of Alsace, then to Flanders again, to Montdidier, and finally was officer in charge of 4,000 beds at Pontoise. His war work gave rise to numerous special studies and four major researches. First, thoracic surgery where he advocated direct intervention for chest wounds. His results and theories were published in his *Plaies de guerre du poumon* 1918. Secondly, he was a fervent and successful advocate of serotherapy for the prevention of gas gangrene. Thirdly, he introduced the practice of delayed primitive suture in the armies under his charge; that is to say, excision of wounds was to be effected in the field and primitive suture completed some days later at the base. Finally, he studied traumatic shock, proving its toxic origin in the chemical breakdown of the injured tissues. He was awarded the Croix de Guerre with a bar, and created Chevalier of the Légion d'Honneur 1915, promoted Officier in 1918, and became Commandeur in 1934. He was sent on special missions to the Belgian and British armies, to Italy, and to America. He was elected to the Association of Surgeons of Great Britain, to the American College of Surgeons, and on 2 February 1920 an Honorary Fellow of the Royal College of Surgeons. Returning to civil practice, Duval became surgeon to the Lariboisière Hospital and was elected professor of operative surgery in the Paris Faculty 1919. Two years later he was made head of the new University Hospital at Vaugirard, and professor of clinical surgery. Here he established a surgical clinic after his own heart, supported by a battery of specialist subsidiaries, medical, biochemical, radiological, etc. Duval took a particular interest in the radiological study of his surgical cases. Duval was now the centre and head of an elaborate team, whom he inspired to fulfil his conception of physiological surgery, a conception similar to Moynihan's "pathology of the living". A vast output of surgical research came from Duval and his team in the twenty years remaining to him. He worked again on various aspects of surgery of the large intestine, thoracic surgery, duodenal ulcer. In particular he stressed the importance of pre-operative treatment of bacterial infection in cases of ulceration. He advocated urgent gastrectomy for perforated ulcer. His *Etudes médico-radio-chirurgicales sur le duodenum*, with J-Ch Roux and H Béclère, was an outstanding contribution to the subject, and differentiated three distinct affections previously confused (1924). Duval explored and improved the surgery of the pancreas, gall bladder, liver, and spleen. In 1931 he opened a crusade on behalf of immediate intervention, in the first 24 hours, in all cases of appendicitis. But his most important work was his study of post-operative toxicity, and of general infection after burns. Both arose from his earlier work on shock and were inspired by his ideal of physiological surgery and his realization of the importance to the surgeon of biochemical investigation. Duval was throughout his career an inspiring teacher, of dynamic intellect, to whom his pupils and assistants became devoted friends. Duval served as president of the Society (now Academy) of Surgery in 1932, and had become president of the Academy of Medicine in January 1941, just before his sudden death. He had travelled widely in Europe and North and South America, and was a corresponding member of the surgical academies of numerous capitals. When war began again in September 1939, Duval took an active part in the background of medico-military work. He was a prompt supporter of the introduction of sulfonamide treatment. When Paris fell in June 1940, he remained at his post at Vaugirard, and carried on his surgical work, both clinical and research, with unabated energy. He married Carmen Laffitte, whose death between the wars was a great shock to him. Their sons distinguished themselves: Charles-Claude, a lawyer, married a daughter of M Deschamel, at one time President of the Republic, and Paul-Marie became professor of geology at the Sorbonne. Duval died after a very short illness on 7 February 1941, survived by his sons, the younger of whom was a prisoner-of-war in Germany at the time of Pierre Duval's death. He had lived at 119 Rue de Lille, Paris. Duval was a man of great beauty of character, and wide interests, warm-hearted though a little formal, and absolutely upright.