He was born into an aristocratic family, the fourth and last son of Marquis Riccardo Trionfi, owner of ships employed in trade with the Americas during the nineteenth century; he was initiated into a military career like his brothers Giuseppe (who would become an Admiral in the Regia Marina) and Luigi (who would also become a General).

[2] When the Red Army reached the Vistula in January 1945, the Nazis decided to evacuate the camp and transfer the prisoners to Luckenwalde, a town south of Berlin, with a forced march.

Along with sixteen other prisoners (the weakest of the column, who were too exhausted to continue the march and made a stop with the permission of the German commander, who however refused to write a statement that they had been left behind with his consent rather than escaped), Trionfi stopped on the way, in Kuźnica Żelichowska, looking for food in a tavern; the group was however noticed by a non-commissioned officer of the Luftwaffe and reported to the SS.

[5][6][7][8][9][10] In May 1945 Trionfi's family was wrongly notified by the Italian embassy in Moscow that he was alive and in good health, but on the following month they received a letter of apology with the news of his death.

[1][2][11] The general's daughter, Maria Trionfi, managed to identify the SS officer who had ordered the massacre with the help of Simon Wiesenthal and tried to have him brought to justice, but without success.