of NICOMEDEIA, the friend and protector of Arius, was maternally connected, though distantly, with the emperor Julian, and born about A. D. 324. He was first bishop of Berytus (Beyrout) in Syria, and then of Nicomedeia, which Diocletian had made his residence, so that it was in fact the capital of the Eastern empire till Constantine fixed his court at Byzantium. He first comes under the notice of history by taking the part of Arius after his excommunication by Alexander, bishop of Alexandria. [ARIUS.] He wrote a defence of the heretic to Paulinus, bishop of Tyre, and the letter is preserved in Theodoret (1.6). Eusebius states in it his belief that there is one Being Unbegotten and one Begotten by Him, but not from his substance, having no share in the nature or essence of the Unbegotten, but yet πρὸς τελείαν ὁμοιότητα διαθέσεως τε καὶ δυνάμεως τοῦ Πεποιηκότος γενόμενον.

So warmly did Eusebius take part with Arius, that the Arians were sometimes called Eusebians; and at the Nicene council he exerted himself vigorously against the application of the term ὁμοούσιος to the Son. But his opposition was unsuccessful, the Homoousians triumphed, and Eusebius joined his namesake of Caesareia in affixing his signature to the Creed, though he took the word in a sense which reduces it merely to ὅμοιος κατ̓ οὐσίαν.

He declined, however, to sign the anathema which the council issued against Arius, though not, as he says in the petition which he afterwards presented to the bishops, "because he differed from the doctrine as settled at Nicaea, but because he doubted whether Arius really held what the anathema imputed to him." (Soezom. 2.15.) But very soon after the council had broken up, Eusebius shewed a desire to revive the controversy, for which he was deprived of his see and banished into Gaul. On this occasion Constantine addressed a letter to the people of Nicomedeia, censuring their exiled bishop in the strongest manner, as disaffected to his government, as the principal supporter of heresy, and a man wholly regardless of truth. (Theodor. Hist. Eccl. 1.20.) But he did not long remain under the imperial displeasure. Constantia, the emperor's sister, was under the influence of an Arian presbyter, and was thereby induced to plead in favour of that party with her brother, and one result of her interference was the restoration of Eusebius to his see; and he soon so completely regained Constantine's favour, as to be selected to administer baptism to him in his last illness. His Arian feelings however broke out again. He procured the deprivation ot Eustathius, bishop of Antioch, and, if we may believe Theodoret (1.21), by suborning a woman to bring against him a false accusation of the most infamous kind He was an active opponent of Athanasius, and exerted himself to procure the restoration of Arius to the full privileges of churchmanship, menacing Alexander, bishop of Constantinople, with deposition unless he at once admitted him to the holy communion, in which he would have succeeded but for the sudden death of Arius. Soon after this Alexander died, and Eusebius managed to procure his own election to the vacant see, in defiance of a canon against translations agreed to at Nicaca. IIe died about A. D. 342.

Though Eusebius lies under the disadvantage of having his character handed down to posterity almost entirely by the description of theological enemies, yet it is difficult to imagine that he was in any way deserving of esteem. His signature to the Nicene creed was a gross evasion, nor can he be considered to have signed it merely as an article of peace, since he was ever afterwards a zealous oppotent of its principles. It can scarcely be doubted that he was worldly and ambitious, and if Theodoret's story above referred to be true, it would be horrible to think that a Christian bishop should have been guilty of such gross wickedness. At the same time, considering the entire absence of the critical element in the historians of that age, the violent bitterness of their feelings on subjects of theological controversy, and the fact that Theodoret wrote many years after Eusebius's death, we shall be slow to believe in such an accusation, which rests only on the authority of the most vehement of the church historians of the time, while Socrates, the most moderate and least Orednlous, merely says (1.18), that Eustathius was deposed nominally for Sabellianism, " though some assign other causes;" and Sozomen (2.18) tells us, that some accused Eustathius of leading an irregular life, but does not hint that this charge rested on a wicked contrivance of Eusebius. Athanasius himself gives another cause for the deposition of Eustathius--that Eusebius had accused him of slandering Helena, the mother of Constantine. (Athan. Hst. Ari. § 5.) We regret in this instance, as in others, that we have not the complete work of Philostorgius, the Arian historian, who, however, in one of his remaining fragments, does not hesitate to attribute miracles to Eusebius. (Waddington, Church Hist. ch. vii.) Athanasius (Orat. ii.) considers him as the teacher rather than the disciple of Arius; and afterwards, when the Arians were divided among themselves into parties, those who maintained the perfect likeness which the substance of the Son bore to that of the Father (Homoiousians) against the Consubstantialists, on the one hand, and the pure Arians, or Anomoians, on the other, pleaded the authority of this Eusebius. The tenets of this party were sanctioned by the Council of Seleuceia, A. D. 359. (Theodor. l.c. ; Sozom. l.c.; Socrates, 2.5; Cave, Hist. Lit. vol. i.; Neander, Kirchengeschichte, vol. ii. p. 773, &c.; Tillemont, sur les Ariens, art. 66; see also an encyclical letter from the synod of Egyptian bishops to be found in Athan. Apol.c. Ar. § 10.)