Morgagni was born in Forlì-Cesena in 1879. His father was Andrea Morgagni, and his mother was Giulitta Monti. He is the brother of another prominent journalist,
Tullio Morgagni. Morgagni gained a diploma from a commercial college. He was initially a supporter of socialist trade unions. He supported Italian intervention in World War I. From 15 November 1914 to 1919, he was administrative director of ''
Il Popolo d'Italia'', a newspaper he co-founded with
Benito Mussolini. He turned the illustrated newspaper toward support of Fascism, including publishing lavish coverage of Fascist rallies, using foldout panorama images. Along with his brother, Tullio Morgagni, he was one of the founders of the Italian long-distance bicycle race, the
Giro d'Italia, under the sponsorship of rival newspapers. In 1919,
Arnaldo Mussolini became director of the newspaper, while Morgagni remained in charge of advertising. Morgagni became active in civic politics in
Milan, serving as a city councillor from 1923 to 1926, and then as mayor of Milan from 1927 to 1928. In 1928, he founded the
agricultural newspaper Nature. ==Agenzia Stefani and Mussolini==