Born on 28 August 1880 at Audenarde, Belgium, where his father was serving as an Army veterinary officer, he was educated at Antwerp and Louvain, and graduated in medicine from the Free University of Brussels. As assistant to Antoine Depage 1904-09 he was engaged in thoracic surgery and devised an apparatus for deep narcosis, constructed for him by Collin of Paris, to preclude pulmonary collapse after opening the thorax. He next turned to vascular surgery, and his thesis for "aggrégé de chirurgie" in 1912 was on vascular anastomoses and ligatures; in 1913 he was awarded the Prix Seutin for his pioneer work on trans-sacral anaesthesia. As surgeon to out-patients at the Hospice de l'Infirmerie in Brussels from 1913 to 1920 he performed major operations in many branches of surgery under local anaesthesia for ambulant patients, whom he followed up in their own homes. He was surgeon to the Gynaecological Clinic from 1920 to 1925, and was then appointed Professor of Clinical Surgery in the Université libre de Bruxelles, becoming full-time Professor of Surgery in 1930, and working as chief of surgical service first at the Brugmann and later at the St Pierre Hospital. The Belgian Royal Academy of Medicine published in 1928 his important memoir on surgical treatment of cancer of the breast, in which he introduced an improved modification of Halsted's operation, which was widely adopted in French-speaking countries as the Danis-Depage method. He began in 1930 the operative treatment of fractures, which became his main concern till he retired in 1946. This won him international fame, though it was his breast-cancer operation which made a marked impression on the surgeons who gathered at Brussels in 1938 for the International Congress. Danis was long active in the International Society of Surgery, following the example of his master Depage; and became President in 1951. The objectives of his orthopaedic work were perfect reduction of the bone fragments and firm synthesis without immobilisation of the adjacent joints. He was an accomplished engineer, making his own special instruments and machine tools, and also studied the mechanical problem of interfragmentary pressure in the process of ossification. He surveyed his achievement in a notable book *Théorie et Pratique de 1'Ostéosynthèse*, Paris 1949, 2nd edition 1951. Danis was an excellent teacher, caustic but friendly to his pupils for all of whom he made nicknames. His classes were informal but very much to the point, and he drew well with either hand to illustrate his lectures. The Professor of Surgery was known traditionally as "le patron" and it was a tribute to Danis that he was called "le grand patron". In his younger days he had travelled in Africa as a big-game hunter, and later was consulted by the Belgian Government and by the medical services in the Congo. He was honoured by many universities and societies, was elected an Honorary Fellow of the College in 1947 and was an Honorary Fellow of the Association of Surgeons. He kept up a large international correspondence, being an excellent linguist. At the time of his death he was President elect for 1963 of the Académie royale de Médecine de Belgique. His mother had given him as a boy a thorough training in music; he studied harmony and counterpoint, and played the piano and violin and in later years the guitar also, His music room contained an electronic organ which reproduced almost any instrument. In the last years of his life he spent many hours composing and recording on a tape recorder. He was a capable painter in oil and water-colour, and an etcher; also an accomplished cook and a bon viveur. He died on 3 July 1962 aged nearly 82, survived by his son, a surgeon.