For the Franco-Irish saint, see Sidonius of Saint-Saëns.Gaius Sollius (Modestus) Apollinaris Sidonius or Saint Sidonius Apollinaris (November 5 of an unknown year, perhaps 430 – August 489) was a poet, diplomat, and bishop. Sidonius is "the single most important surviving author from fifth-century Gaul" according to Eric Goldberg.