Yilma was educated at the London School of Economics, becoming a member of the Ethiopian pre-war intelligentsia; according to Spencer he was both fluent and eloquent in English, speaking it at home with his wife Elizabeth, and along with "Dejazmach" Zewde Gebre Selassie was the only member of his generation "who attempted to keep up with current literature" in his field. Following the defeat of the Ethiopian armies in the Second Italo-Abyssinian War, he became a member of the Black Lions, but surrendered with "Ras" Imru Haile Selassie near the Gojeb River 19 December 1936. Because he was interned on Ponza with "Ras" Imru, he avoided the murderous retribution following the attempted assassination of Rodolfo Graziani 19 February 1937.