Note 010
Theodoret (1. i. c. 18) seems to insinuate that Helena gave her son a Christian education; but we may be assured, from the superior authority of Esebius (in Vit. Constant. 1. iii. c. 47), that she herself was indebted to Constantine for the knowledge of Christianity.
Note to Chapter 20 of DECLINE & FALL by Gibbon