As to the date of St. Basil's birth opinions have varied between 316 and 330. The later, which is supported by Garnier, Tillemont, Maran,  Fessler,  and Boehringer, may probably be accepted as approximately correct.  It is true that Basil calls himself an old man in 374,  but he was prematurely worn out with work and bad health, and to his friends wrote freely and without concealment of his infirmities. There appears no reason to question the date 329 or 330.
Two cities, Caesarea in Cappadocia and Neocaesarea in Pontus, have both been named as his birthplace. There must be some amount of uncertainty on this point, from the fact that no direct statement exists to clear it up, and that the word patris was loosely employed to mean not only place of birth, but place of residence and occupation.  Basil's parents had property and interests both in Pontus and Cappadocia and were as likely to be in the one as in the other. The early statement of Gregory of Nazianzus has been held to have weight, inasmuch as he speaks of Basil as a Cappadocian like himself before there was any other reason but that of birth for associating him with this province.  Assenting, then, to the considerations which have been held to afford reasonable ground for assigning Caesarea as the birthplace, we may adopt the popular estimation of Basil as one of "The Three Cappadocians,"  and congratulate Cappadocia on the Christian associations which have rescued her fair fame from the slur of the epigram which described her as constituting with Crete and Cilicia a trinity of unsatisfactoriness.  Basil's birth nearly synchronizes with the transference of the chief seat of empire from Rome to Byzantium. He is born into a world where the victory already achieved by the Church has been now for sixteen years officially recognized.  He is born into a Church in which the first great Council has already given official expression to those cardinal doctrines of the faith, of which the final and formal vindication is not to be assured till after the struggles of the next six score of years. Rome, reduced, civilly, to the subordinate rank of a provincial city, is pausing before she realises all her loss, and waits for the crowning outrage of the barbarian invasions, ere she begins to make serious efforts to grasp ecclesiastically, something of her lost imperial prestige. For a time the centre of ecclesiastical and theological interest is to be rather in the East than in the West.
 329. Prudent Maran, the Ben. Ed. of Basil, was a Benedictine exiled for opposing the Bull Unigenitus. /-1762.
 "Natus. c. 330."
 Gregory of Nazianzus, so called, was born during the episcopate of his father, Gregory, bishop of Nazianzus. Gregory the elder died in 373, after holding the see forty-five years. The birth of Gregory the younger cannot therefore be put before 328, and Basil was a little younger than his friend. (Greg. Naz., Ep. xxxiii.) But the birth of Gregory in his father's episcopate has naturally been contested. Vide D.C.B. ii. p. 748, and L. Montaut, Revue Critique on Greg. of N. 1878.
 Ep. clxii.
 Gregory of Nazianzus calls Basil a Cappadocian in Ep. vi., and speaks of their both belonging to the same patris. In his Homily In Gordium martyrem, Basil mentions the adornment of Caesarea as being his own adornment. In Epp. lxxvi. and xcvi. he calls Cappadocia his patris. In Ep. lxxiv., Caesarea. In Ep. li. it is doubtful whether it is Pontus, whence he writes, which is his patris, or Caesarea, of which he is writing. In Ep. lxxxvii. it is apparently Pontus. Gregory of Nyssa (Orat. I. in xl. Mart.) calls Sebaste the patris of his forefathers, possibly because Sebaste had at one time been under the jurisdiction of Cappadocia. So in the N.T. patris is the place of the early life and education of our Lord.
 Maran, Vit. Bas. i.
 Kappadoches, Koetes, Kilikes, tria kappa kakista. On Basil's own estimate of the Cappadocian character, cf. p. 153, n. cf. also Isidore of Pelusium, i. Epp. 351, 352, 281.
 The edict of Milan was issued in 313.
Reference address : https://www.elpenor.org/basil/life-works.asp?pg=2