Born at Allahabad on 6 September 1873 the son of the Hon Sir George Knox, afterwards a Judge of the High Court of the North-West Provinces of India, and Katherine Anne Louise Loch his wife, he was educated at Westminster School and entered Caius College, Cambridge in October 1890, but migrated after two terms to Edinburgh University where he qualified in 1896. He was commissioned Surgeon-Lieutenant in the Indian Medical Service in 1897, promoted Captain in 1900 and Major in 1909, and was awarded the Kaisar-i-Hind medal (first class) in that year. He served as agency surgeon to the Foreign and Political department of the Government of India, and as residency surgeon at Hyderabad. When war broke out in 1914 he was sent to Egypt, saw active service at Gallipoli (1915) and was Assistant Director of Medical Services to the 60th Division, Egyptian Expeditionary Force in Palestine 1916-18. He was awarded the DSO in 1915 and mentioned in dispatches in 1916-17-18. He received the Serbian Order of the White Eagle, fourth class, in 1917 and was made an Officer of the Order of the Crown of Italy in 1919. He had been promoted Lieutenant-Colonel in 1917, and on his return to India was made chief medical officer of the King Edward Memorial Hospital at Secunderabad. He was promoted full Colonel in 1924 on his appointment as Assistant Director of Medical Services for the Peshawar district, was appointed an honorary surgeon to the King-Emperor in 1927, and retired in 1928. In 1924 he served as honorary secretary of the Hyderabad and Central Provinces branch of the British Medical Association. He settled at Millersholt, Woodgreen, Fordingbridge, near Salisbury, where he took a leading part in local life for thirty years. He had married his cousin Lilian, daughter of Colonel J L Loch; their daughter Mrs Anderson survived him. He died in her house, 67 Landsdowne Road, London W, on 20 January 1959 aged 85.