Maximinius was born at Silly near Poitiers in France. As a young man, he heard of a saintly bishop of Trier, in Gaul. He traveled to that city and became a disciple of St. Agritius. This holy bishop saw to it that Maximinius received a good education.

After many years of study and preparation, Maximinius became a priest and then bishop. He took over the diocese of Trier. Bishop Agritius could not have been more pleased. He knew that his people would have a wonderful bishop.

When St. Athanasius of Alexandria, Egypt, was sent into exile to Trier, St. Maximinius welcomed him. He did everything to help Athanasius and to make his time away from his people less painful. Another brave bishop of those times, St. Paul, bishop of Constantinople, was also protected by Maximinius from the anger of Emperor Constantius.

St. Athanasius wrote that Maximinius was brave, holy and a well known as a miracle worker. Because he was a great man, he was willing to defend the Church of Jesus from the Arians and others who attacked it.

He was willing also to protect those brave bishops who fell out of favor with the political powers. Maximinius put his own life in danger even if he had to lose his position or his life, if necessary. He died around the year 347 and his body was buried in the church of Saint John near Trier in Germany.