Major Robert Yelverton Stones graduated MB, BS in 1907 and gained the DPH in 1908 and the FRCS Ed in 1910. He sailed for Africa in 1911 as a missionary of the Church Missionary Society. He first worked at Iyi Enu Hospital, Nigeria, and in 1913 was transferred to Old Cafro Mission Hospital in Egypt.
During the first world war he was commissioned in the RAMC and served first in the near East and then in German East Africa, being awarded the Military Cross. At the end of the war he began missionary work again in Tanganyika, doing outstanding service in the famine at Dodoma in 1919. From Dodoma he went to Maseno in Kenya, near Lake Victoria, where he founded a hospital with Red Cross funds. Continuing to win academic honours, he proceeded MD in 1918 and took the MRCP in 1925 and the DMRE in 1930.
In 1924 Major Robert Yelverton Stones travelled to Uganda and joined Dr (afterwards Sir Albert) Cook at Mengo Hospital, Kampala, the mission hospital which Cook had founded in 1897. He worked there until 1939, latterly as medical superintendent, and was appointed OBE in 1938 for his services.
He returned to England in 1939, but as he could not reconcile himself to a quiet life at home, he joined the RAMC and was in Malta during the siege and stayed on afterwards for a time in charge of the King George V Hospital for Merchant Seamen Floriana.