Ras Mulugeta Yeggazu was born in Manz, an Amhara region of the province of Shawa. He was related to Emperor Menelik II, and was a descendant of Tedu, a 18th-century hero.
Mulugeta served as Minister of Finance during the last years of Emperor Menelik II's reign (who died in 1913) and from 1916 to 1918 he was appointed Minister of Foreign Affairs thanks to the intercession of the heir to the throne, Tafari Makonnen, who appreciated and trusted him. However, the country entry into the Weltkrieg on the side of Germany in 1918 and the subsequent annexation of Italian Somaliland and Eritrea increased the power of the conservative faction that supported Empress Zauditu who was able to extert a greater control on the government and dismissed him.
In 1922 he was appointed Governor of Begemder and in 1923 he followed Tafari Makonnen on his tour of Europe, where he witnessed the technological advance of the european countries. He was particularly interested in the new weapons and army doctrines that had been developed there. When Haile Selassie I ascended to the throne, he appointed him Minister of Finance, but in 1931 he decided to promote him to Imperial Fitawrari and appoint him as Minister of War, in order to undertake a modernization of the Abyssinian Army.
He has a son, Tadessa Mulugeta, and a daughter, Leilt Zuriash.