Almost all that we know of Severus' life comes from a few allusions in his own writings, some passages in the letters of his friend Paulinus, bishop of Nola, and a short biography by the historian Gennadius of Massilia.
Born of noble parents in Aquitaine, Severus enjoyed excellent educational advantages. He was imbued with the culture of his time and of his country, a center of Latin letters and learning. He studied jurisprudence and was renowned as an eloquent lawyer; his knowledge of Roman law is reflected in parts of his writings. He married the daughter of a wealthy consular family, who died young, leaving him no children.
At this time Severus came under the powerful influence of Saint Martin, bishop of Tours, by whom he was led to devote his wealth to the Christian poor, and his own powers to a life of good works and the contemplative vision of God. This choice incurred his father's displeasure, but was encouraged in his determination by his mother-in-law. To use the words of his friend Paulinus, he broke with his father, followed Christ, and set the teachings of the "fishermen" far above all his "Tullian learning." He rose to no higher rank in the church than that of presbyter. His ordination is vouched for by Gennadius, but no details of his priestly activity have reached us. He is said to have been led away in his old age by Pelagianism, but to have repented and inflicted long-enduring penance on himself. His time was passed chiefly in the neighbourhood of Toulouse, and such literary efforts as he permitted to himself were made in the interests of Christianity.
In many respects no two men could be more unlike than Severus, the scholar and orator, well versed in the ways of the world, and Martin, the rough Pannonian bishop, champion of the monastic life, seer and worker of miracles. Yet the spirit of the rugged saint subdued that of the polished scholar, and the works of Severus are important because they reflect the ideas, influence and aspirations of Martin, the foremost ecclesiastic of Gaul.