Mario De Maria was born in Bologna into a family with an artistic pedigree: his great-grandfather had been the orchestra director at St Petersburg, while his paternal grandfather, had been a Neoclassical sculptor. Mario enrolled in the Bolognese Academy of Fine Arts in 1872, and studied there irregularly until 1878. After moving to Rome, he became friends with Vincenzo Cabianca and, for a few years, exhibited his characteristic moonlights with the Roman group In Arte Libertas of Nino Costa, close to the Pre-Raphaelites. In 1892 he moved to Venice, frequenting the social life of the city, then dominated by the presence of Gabriele D'Annunzio and Eleonora Duse. De Maria was among the creators of the Venice Biennale, of which he was then organizer and exhibitor for a long time and in 1909 the Biennale dedicated a retrospective to him. Another monographic exhibition at the Venice Biennale was held in 1926, shortly after his death. His glory was soon overshadowed, by the onslaught of the avant-garde, by the accusation of Passatismo, which contributed, together with family bereavements, to isolate and marginalize him from the spotlight of the artistic scene.