Son of a Gothic general, and member of a noble military family. Studied at the seminary in Palencia. From an early age, Fructuosus felt a call to the religious life. Orphaned when young. When he came of age, Fructuosus gave away his family fortune to the poor, bought the freedom of slaves, and founded several monasteries. By 647 he had founded houses in Lusitania, Asturia, Spanish Galicia, and the island of Gades.

Feeling that he lacked contact with God, Fructuosus left the houses and friends, and became a hermit in the desert of Galacia. His reputation for holiness and wisdom attracted students, sometimes entire families. He built monasteries for them, placed them under the Benedictine Rule, and served as abbot. He attracted so many disciples that the king limited the number of men who could join; he feared there would not be enough young men to man the army.

Again feeling that the outside world was taking too much of this time, Fructuosus planned to flee further into the wilderness, this time to the deserts in Egypt. However, the king got word of the plan, decided too many people depended on his leadership, and ordered him not to leave the country. Bishop of Dumium in 654. Archbishop of Braga, Portugal in 656. Wrote two monastic rules, one of which was designed to allow families to remain together, yet live monastic lives.