His nascent singing career was put on hold, however, by the outbreak of World War I in 1914, during which he served with the Italian armed forces and emerged as one of Italy's most decorated soldiers. The war over, he made a successful operatic debut as Arturo in Bellini's "I Puritani" in Viterbo, Italy, on 2 September 1919—performing under the name Giacomo Rubini, after Bellini's favorite tenor, Giovanni Battista Rubini. Four months later, on 3 January 1920, he scored another success, at the Teatro Costanzi in Rome, this time performing under his own name opposite Rosina Storchio and Ezio Pinza in Massenet's "Manon".