A deacon martyred in the Val di Non in Italy in 397, alongside companions Martirio and Alessandro, evangelizing an Alpine valley.

Saint Sisinnio was a deacon martyred in the Val di Non, an Alpine valley in present-day Italy, on May 29, 397, together with his companions Saints Martirio and Alessandro. The three had been sent as missionaries to evangelize the still largely pagan Alpine population, and their deaths came as a direct result of resistance to that mission.

Quick Facts

• Died: May 29, 397, at Val di Non, Italy
• Venerated as: Deacon and martyr
• Companions: Saints Martirio and Alessandro

Who Was Saint Sisinnio?

Sisinnio served as a deacon and took part in a missionary effort to bring Christianity to the Val di Non, an Alpine valley in present-day Trentino, Italy, that remained largely pagan even as Christianity had become the empire’s dominant religion elsewhere. He was martyred there in 397 alongside his companions Martirio and Alessandro.

Historical Setting

By the late fourth century, Christianity held official imperial favor across much of the Roman world, but remote mountain regions like the Val di Non retained strong pagan traditions and sometimes resisted evangelization violently, making missionary work there still genuinely dangerous.

Why the Church Remembers Saint Sisinnio

Sisinnio is remembered as part of a small missionary team, sent by Bishop Vigilius of Trent, whose martyrdom in the Val di Non became a founding story for the Christianization of the Alpine region, their deaths ultimately advancing the very mission that cost them their lives.

Canonization and Feast Day

No formal canonization process is recorded for Sisinnio. His veneration, shared with his companions Martirio and Alessandro, rests on the ancient cult of the Diocese of Trent, sustained through liturgical memory since the late fourth century.

What Catholics Can Learn Today

Sisinnio’s death during active missionary work is a reminder that evangelization has often required real courage in the face of genuine resistance. His witness honors all who bring the Gospel to places where it is not yet welcomed.

A Prayer to Saint Sisinnio

Saint Sisinnio, deacon and missionary martyr of the Alps, you gave your life bringing Christ to those who did not yet know him. Inspire courage in missionaries who labor in resistant places today. Amen.

Sources

• Roman Martyrology
• Local tradition of the Diocese of Trent, Italy