Roberta Cowell , born Robert Marshall Cowell , father of two , whose sensational change of sex ( man to woman ) confounded the world when revealed in 1954, made medical and press history . It is believed that such a complete and perfrect transformation of this kind has no precedent . Photo shows: Robert Cowell with his bride at the Croydon Registry Office , Surrey In May 1941 . Cowell was then an officer in the Royal Army Service Corps .. He was transferred to the RAF soon afterwards and was an ace fighter pilot .