He was born in Fabriano, province of Ancona, on 17 June 1897, the son of Donato Mastromattei and Giovanna Carrozzo.Angelo Fortunato Formiggini, Chi è? Dizionario degli Italiani d'oggi, p. 193 After graduating from a technical institute, he volunteered at age eighteen during the First World War, becoming an Alpini officer and being wounded and decorated for valor, ending the war with the rank of captain (later promoted to major).Istituto del Nastro Azzurro After the war he joined the sansepolcrismo in 1919 and became one of the leading figures of the Italian Fasces of Combat of Genoa, as well as a squadrista, participating in the storming of Palazzo San Giorgio (seat of the Socialist cooperatives of Genoa) and of the Chamber of Labour of Genoa.I prefetti del Regno nel Ventennio fascistaMaurizio Lamponi, Il fascismo in Valpolcevera, pp. 2-3Le opzioni come tradimento dell’HeimatIpertesti de La Provincia di Bolzano In 1920-1921 he was secretary of the Genoa section of the Fasces of Combat, then regional secretary for Liguria in 1921, and federal secretary of Genoa from March to December 1921.I prefetti del Regno nel Ventennio fascistaMaurizio Lamponi, Il fascismo in Valpolcevera, pp. 2-3Ipertesti de La Provincia di Bolzano
