Life and Episcopate
Leontius was born toward the end of the fourth century, probably in the city later called Nîmes, to a noble Gallo-Roman family. Sources note that he was likely the brother of Saint Castor, Bishop of Apt, another prominent ecclesiastic of early fifth-century Provence who was himself a patron of John Cassian's writings; if the kinship holds, the two represent two episcopal figures drawn from the same noble family of Nîmes.
He was raised to the see of Fréjus in Provence at some point between the years 400 and 419. Tradition remembers him as a man of eminent sanctity whose episcopate was marked by important results. He became an early patron of the cathedral church of Fréjus, which was dedicated to him alongside the Blessed Virgin Mary and served as the seat of the Bishop of Fréjus from the fifth century until 1957.
He died in his episcopal city around 448, though some accounts give the year as 443.
Lérins and the Monastic Foundation
Leontius ordained Honoratus and encouraged him to take up his abode on the wild island of Lérins, where Honoratus, seeking a life of solitude, established the monastery that became the celebrated Lérins Abbey at the beginning of the fifth century. Honoratus is said to have called Leontius his superior and his father.
Leontius granted special privileges to the monastery while retaining episcopal dignity over it. These arrangements were later confirmed by the Third Council of Arles and became important early precedents in the developing question of monastic immunities.
John Cassian and the Conferences
John Cassian, who directed the Abbey of Saint Victor at Marseille, dedicated the first series of his Conferences to Leontius, a mark of the bishop's spiritual standing in the region. The Conferences set down the spiritual conversations Cassian had held with the desert elders of Egypt and were arranged in three sets; the first collation (Conferences 1–10) treats such subjects as the goal of the monk, discretion, the three renunciations, the passions, and prayer, and its dedication names the bishop of Fréjus together with the monk Helladius.
A later notice records that in 445 Pope Leo the Great granted Leontius privileges formerly held by Hilary of Arles, though historians debate whether this refers to the same Leontius or to a successor of the same name.
