Bishop of Cæsarea, in which see he preceded Dianius.  cf. Letters ccxliv. 9 and cclxiii. 3.  “The great Synod” is Nicæa.  Baronius on the year 325 remarks that Basil’s memory must have failed him, inasmuch as not Hermogenes but Leontius was present at Nicæa as Bishop of Cæsarea.  But Hermogenes may have been present in lower orders.  cf. Stanley, East. Ch. pp. 105, 140.