Zepherin Namuncura was the eighth of twelve children of the chief of the Araucano Indians of the Argentine Pampas, Chief Manuel Namuncura.Zepherin's ambition was to lead his people to the religion of the one true God. When Zepherin was two, his father gave him to the Salesian priest, Father Dominic Milanesio, telling him that he was giving this son, the future leader of his people, to be brought up in the white man's religion. Zepherin was educated at the Salesian mission school in Buenos Aires. At the age of seventeen, he went into the seminary where he studied hard enough to become second in his class. Zepherin was also growing in virtue and was often found in front of the Blessed Sacrament.

On September 24, 1903, with the permission of his Superiors, Zepherin organized a procession in honor of Our Lady of Mercy. That night he fell into bed tired from his day's labor. He awoke coughing and spitting up blood. Zepherin had tuberlosis. In April of 1904, Zepherin accompanied Archbishop Cagliero to Rome where it was thought that the warm dry air might be good for his health.

In March of 1905, Zepherin took a sudden turn for the worse. He lost weight alarmingly, and seemed to be often in pain. His director wrote, "He got worse day by day, yet he was never impatient. He suffered, but he held onto his cross generously." In April, Zepherin was transferred to the hospital run by the Brothers of God in Rome. Here he bore his cross of suffering heroically, constantly praying the Rosary for his people. This saintly seminarian died on the morning of May 11, at the age of eighteen, surrounded by several of the brothers who were praying for him. He was buried in Rome, but at the insistence of his people, his body was taken back to Patagonia in 1924 and buried at the Salesian school of Fortin Mercedes. Zepherin was declared Venerable by Pope Paul VI in 1972.