Pelagius was probably born around 350 CE in Britain (Aug. Ep. 186.1; Marius Mercator, Commonitorium lectori adversum haeresim Pelagii et Caelestii vel etiam scripta Iuliani in ACO 1.5.1.5; Oros. Lib. apol. 12) or, less probably, in Ireland, according to Jerome (Comm. Jer. 3, prologue 4). He is described by his adversaries as a robust and fat man (Oros. Lib. apol. 31; Jer. Comm. Jer. 1, prologue 4; 3, prologue 3), though the reliability of this description cannot be completely assured. Nonetheless, Augustine of Hippo recogni…