He was born in Rome on 2 August. 1888, by Adolfo and Emma Mirone. After being orphaned of his father, G. spent his childhood and adolescence with his mother in Rome, where he attended the Academy of Fine Arts and the free school of the nude, and where he became friends with G. Severini.
In the meantime, futurism, with the publication of the first poster on Le Figaro in 1909, had imposed itself on the attention of the Parisian artistic circles. G. soon joined the futurist group, as evidenced by his correspondence with Severini and Marinetti (Drudi Gambillo - Fiori, pp. 302, 338). G.'s position within the futurist group appears to be strongly compromised by the violent opposition of C. Carrà and U. Boccioni, who did everything possible to exclude him from the group's activities. In fact, Carrà considered G. and others as imposters who "saying they are futurists make us an anti-clam that bears disastrous results for all of us" (ibid., P. 319)In the first half of the 1920s its activity was very intense and extremely diversified. The pictorial activity of G. developed around the central themes of futurism, as can be seen in the oil painting The motorcyclist of 1918 (Rome, private collection: Crispolti - Sborgi, repr. P. 108), where the exaltation of the machine and the myth of speed are associated according to Marinetti's dictates. In 1919 he wrote a novel entitled The shows of the other world.
His painting of these years, although inspired by futurist experiences, is however free from that formalism and is resolved in an essential and meditative abstraction, with strong poetic accents, especially in the chromatic intensity. However, that inventiveness that had characterized the artist's first period now seems to give way to the meditative and melancholic atmosphere of these paintings. "The painter is not an intellectual, but an instinctive, and the work of art comes from the stomach and not from the brain" declared G. in the presentation for the exhibition held in 1958 at the Venetian gallery Il Cavallino, testifying the will to act within a primary sensitivity.
G. died in Turin on June 7, 1958.