Sidonius married Papianilla, the daughter of Emperor Avitus, around 452. This union produced one son, Apollinaris, and at least two daughters: Sidonius mentions in his letters Severina and Roscia, but a third, Alcima, is only mentioned much later by Gregory of Tours, and Theodor Mommsen has speculated that Alcima may be another name for one of his other daughters. His known acquaintances include bishop Faustus of Riez and his theological adversary Claudianus Mamertus; his life and friendships put him in the center of 5th-century Roman affairs.