Antiochus I Soter
He commenced his reign by putting to death two of his brothers but the third, subsequently called Zipoetes II, 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 Soter, king of the Seleucid Empire, who had already made war upon his father, Zipoetes I, and, to strengthen himself against this danger, he concluded an alliance with Heraclea Pontica and shortly afterwards with Antigonus II Gonatas. The threatened attack, however, passed over with little injury. Antiochus actually invaded Bithynia but withdrew again without risking a battle.