Born 6 June 1884, eldest son of Robert Davies Evans, MRCP Ed, of Blaenau Festiniog, once High Sheriff of Merionethshire, and his wife, who was the eldest daughter of the Rev Thomas Jones and a sister of Sir Robert Armstrong-Jones, FRCS. He was educated at University College, Cardiff, qualified in 1905 when 21, and pursued his medical training at Glasgow, at St Bartholomew's Hospital, London, and in Brussels and Vienna. He served as lieutenant in the 7th Battalion, Royal Welch Fusiliers, 1908-09, and on 31 July 1909 was commissioned a lieutenant in the Indian Medical Service. After taking the Fellowship in 1910 he was appointed surgical specialist in the Lucknow division. He saw active service against the head-hunters at Abor on the North-East frontier in 1911-12, was awarded the medal with clasp, and was promoted captain on 31 July 1912. He served as medical officer to the Mishin expedition, which explored the Tibetan frontier and mapped the upper course of the river Brahmaputra. During the war of 1914-19 he served with the Indian Army at Gallipoli, in Egypt, and in Mesopotamia, where he was civil medical officer for Bagdad in 1917. He was mentioned in despatches 5 November 1915, 13 July 1916, and 27 August 1918, and was awarded the Military Cross 3 June 1916; he was created Chevalier of the Légion d'Honneur 24 October 1919. In 1920 Evans was appointed resident medical officer of the State of Mysore. He was promoted major IMS on 31 January 1921, was knighted on 3 June 1924, and retired on 31 July 1926. On returning to England he settled in practice in London, and became consulting surgeon to St Paul's Hospital for Genito-urinary Diseases. In 1936 he was appointed the first medical superintendent of the Hammersmith Hospital, when the British Postgraduate Medical School was established there. His soldierly qualities showed themselves at their best when he organized the hospital under war-time and air-raid conditions during the war of 1939-45, and took a full personal share in the activities of the hospital's Home Guard detachment. His ten years at the British Postgraduate School were markedly successful. Evans retired in 1945 and settled on the estate which he had bought at Eisteddfor, Criccieth. Here he worked assiduously to modernize the house, gardens, and farm, and took a characteristically active part in the life of the countryside. He was able also to cultivate his lifelong interest in Welsh language, literature, and history, and to continue his generous hospitality. Evans married in 1917 Olwen Elizabeth, elder daughter of the Right Hon David Lloyd-George, PC, MP, Prime Minister, afterwards created Earl Lloyd-George of Dwyfor. After 1921 he was usually known as Carey-Evans. He died suddenly at his home at Criccieth on 25 August 1947, survived by Lady Olwen Carey Evans and their four children, Margaret, Eiluned, Robert, and David, and was buried at Tabor, Pentrefelin.