Compare Idatius and the Paschal Chronicle with Ammianus (1. xiv. c. 5). The year in which Constantius was created Caesar seems to be more accurately fixed by the two chronologists; but the historian who lived in his court could not be ignorant of the day of the anniversary. For the appointment of the new Caesar to the provinces of Gaul, see Julian, Orat. i. p. 12; Godefroy, Chronol. Legum, p. 26; and Blondel, de la Primaute de l'Eglise, p. 1183.