(), king of Bithynia, was the eldest son of
Zipoetes, whom he succeeded on the throne, B. . 278. (Memnon, 100.20, ed. Orell.; Clinton,
vol. iii. p. 411.) Like many other Eastern potentates it appears that he commenced his reign
by putting to death two of his brothers, but the third, Zipoetes, raised an insurrection
against him, and succeeded in maintaining himself for some time in the independent sovereignty
of a considerable part of Bithynia. Meanwhile, Nicomedes was threatened with an invasion from
Antiochus I., king of Syria, who had already made war upon his father, zipoetes, and to
strengthen himself against this danger, he concluded an alliance with Heracleia, and shortly
afterwards with Antigonus Gonatas. The threatened attack, however, passed over with little
injury. Antiochus actually invaded Bithynia, but withdrew again without risking a battle. It
was apparently as much against his revolted subjects as his foreign enemies that Nicomedes now
called in the assistance of more powerful auxiliaries, and entered into an alliance with the
Gauls, who, under Leonnorius and Lutarius, were arrived on the opposite side of the Bosporus,
and were at this time engaged in the siege of Byzantium, Hellenism. vol. ii. p. 178), but no particulars are recorded either of the war or the
peace that terminated it. It appears, however, that Nicomedes was left in the undisturbed
possession of Bithynia, which he continued to govern from this time till his death, and which
rose to a high degree of power and prosperity during his long and peaceful reign. In imitation
of so many others of the Greek rulers of Asia, he determined to perpetuate his own name by the
foundation of a new capital, and the site which he chose, in the immediate neighbourhood of
the Megarian colony of Astacus, was so judiciously selected that the city of Nicomedeia
continued for more than six centuries to be one of the richest and most flourishing in Asia.
(Memnon, 100.20; Chil. 3.950.) The foundation of Nicomedeia is placed by Eusebius (l.c.) in Mém. de l'Acad. des inscr. tom. xv. p. 34) to
about the year ZIELAS, and a
daughter, Lysandra; but his second wife, Etazeta, persuaded him to set aside his children by
this former marriage, and leave his crown to her offspring. The latter were still infants at
the time of his death, on which account he confided their guardianship by his will to the two
kings, Antigonus Gonatas and Ptolemy, together with the free cities of Heracleia, Byzantium
and Cius. But, notwithstanding this precaution, his son Zielas quickly established himself on
the throne. [ZIELAS.] (Memnon. 100.22; Arrian ap. Tzetz. Chil. 3.960;