Umberto Mastroianni, son of Vincenzo and his second wife Luigia Maria Vincenza Conte, was born on 21 September 1910 in Fontana Liri, a charming and ancient village in the province of Frosinone.

In 1924 he moved to Rome where he attended the studio of his uncle Domenico located in the central Via Margutta, and the evening drawing classes at the Academy of San Marcello al Corso. In 1926 he moved to Turin and completed his apprenticeship with the sculptor M. Guerrisi. The study of ancient sculpture is documented by a first phase of refined bas-reliefs.

In 1931, first personal exhibition at the Genoa Gallery of Genoa.

In 1933 he exhibited regularly at the national trade unions, he was invited to the Rome Quadrennial, the Promotrici di Torino, the Venice Biennials. Sculpts portraits of archaic taste.

Pictorial works also date back to the early 1940s: they are geometric abstract abstract shapes that acquire a thickness in colored and scraped plaster, cardboard and sacks. After the war and the resistance, Mastroianni turned decisively to a plastic dynamism of Boccionian ancestry. In fact, his research, with direct references to the futurist season, revolves around the study and rendering of dynamic values, understood and conferred in structures intended as the coagulation of lines of force, the generative nucleus of an explosion of gestures blocked by the weight of matter.

In 1947, with Spazzapan and Moreni, the sculptor is among the promoters of the Premio Torino; exhibited at the Bussola in 1948, presented by D. Formaggio. Start working with architects.

In 1951 he held a solo show at the Galérie de France in Paris and his fame became international.

At the Venice Biennale in 1958 he received the Grand International Sculpture Prize; he exhibited for the first time colored cartoons and plastic reliefs in plaster: a group of seven works in the Bozzetti catalog. He creates shapes preferring folded cartoons to create reliefs, on which he intervenes with color and with tools scraping by piercing, cutting and opening the surfaces tumultuously.

In 1961 he exhibited collectively at the Bussola di Torino and presented plastic reliefs at the Pogliani gallery in Rome.

From 1962 he also dedicated to engraving: he held the first etchings exhibition in Rome in the Romero lithograph: he engraved the plates to illustrate the volumes dedicated, among other things, to ‘Soviet poets’ in 1964 and to ‘Satyricon’ in 1969 , as well as various lithographic folders. In 1963 he exhibited engravings, bronzes and jewelery at the Cavourrina gallery in Turin where he later presented a series of colored cartoons, tapestries and sculptures later sent to the Bonino Gallery in New York in 1964.

Throughout the decade he abandoned the poorly treated raw materials, for lead, brass, steel with gold, enamel and semi-precious stones, enamelled silver and plastic materials, obtaining strong chiaroscuro effects, bronze luminosity and gloomy dramatic gorges voltage. Among the cycles: ‘Ritmi’, ‘Fughe’, ‘Cosmic disruptions’.

In 1970 he moved to Marino Laziale and began a so-called ‘astral’ phase in which the reliefs, created virtual distances and depths beyond the surfaces, figuring a progressive transition from chaos to cosmos. The collaboration with the architects continues: with Mollino he designs and builds the Monument to the Fallen for Freedom at the Turin cemetery; with Sacripanti the Mausoleum for Peace of Cassino in 1977. Anthological reviews are dedicated to the sculptor at the Civic Gallery of Modern Art in Turin and at the National Gallery of Modern Art in Rome in 1974. In that of Palazzo Ducale in Urbino in 1977 comes the production of chromatic reliefs, drawings, wooden sketches and engravings was highlighted for the first time.

In 1979-80 the exhibition of chromatic reliefs at Palazzo Diamanti in Ferrara follows. The Monument of Urbino dates back to 1980. In 1981 it was the large Florentine anthology in the Belvedere Fortress. Next to engraved and colored weights, Mastroianni proposes new colored and scraped cardboard from the titles ‘Compenetrazioni’, ‘Folgore’, ‘Organization of signs’. The research of the last decade continues in this direction, favoring works in steel and bronze. In 1984 he exhibited in Brescia the wooden sketches of monuments to the Resistance, polychrome drawings and reliefs. A F.De Santi is responsible for reading the complete series of ‘Bas-reliefs’ from 1975 to 1983, exhibited at the Teatro Sociale in Bergamo; the exhibition is back in 1985 at the Galeria Editalia in Rome. In 1986 the sculptor donated 26 works from the informal period to the Italian State. Exhibits in Aosta the complete series of large cartoons and tapestries. A review of his scenographic activity is proposed to the Caito in 1988. New anthology in 1989 at the Rotonda della Besana. The Imperial Prize is awarded to him in Tokyo. In 1990, in the castle Ladislao di Arpino, the Mastroianni foundation rises. A review of the last twenty years of activity is staged at the Hakome Oper Air Museum in Japan. In 1991 the sculptor took care of the furnishing of the conference hall of the new building of the Court of Appeal in Rome.

In 1997 the imposing statue of St. Francis, commissioned to the Maestro in 1994 by the Mont Blanc Tunnel Company, is located in the border area between Italy and France.

He died in February 1998.