Martini began attending the Venice Academy’s school of nude studies in 1907. He presented work at the first Ca’ Pesaro exhibition in 1908 and was to be a regular participant there for many years to come. Having subsequently made the acquaintance of Gino Rossi and the artists of the Burano School, he went to Paris in 1911 and exhibited work in the Salon d’Automne. He came into contact with the Futurists in Rome and took part in the 2nd Esposizione Internazionale d’Arte della Secessione in 1914. After the war he divided his time between Milan and Vado Ligure. Having adopted the Primitivism of the Valori Plastici group, he held his first solo show at the Galleria Arte, Milan, in 1920 and moved to Rome in 1921. A room was devoted exclusively to his work at the 3rd Rome Biennale in 1925 and his long participation in the Venice Biennale began by invitation in 1926 with the 15th Esposizione Internazionale d’Arte della Città di Venezia. He joined the Novecento Italiano group and took part in their two shows in Milan (1926 and 1929). The 1930s saw a focus on monumental sculpture with works such as Fascist Justice (1937) for the Palazzo di Giustizia in Milan.