Seleucus in Harpers Dictionary of Classical Antiquities (1898)

Surnamed Callinīcus (246-226), the eldest son of Antiochus II. by his first wife Laodicé. The first measure of his administration, or rather that of his mother, was to put to death his stepmother Berenicé, together with her infant son. This act of cruelty produced the most disastrous effects. In order to avenge his sister, Ptolemy Euergetes, king of Egypt, invaded the dominions of Seleucus, and not only made himself master of Antioch and the whole of Syria, but carried his arms unopposed beyond the Euphrates and the Tigris. During these operations Seleucus kept wholly aloof; but when Ptolemy had been recalled to his own dominions by domestic disturbances, he recovered possession of the greater part of the provinces which he had lost. Soon afterward Seleucus became involved in a dangerous war with his brother Antiochus Hierax, who attempted to obtain Asia Minor as an independent kingdom for himself. This war lasted several years, but was at length terminated by the decisive defeat of Antiochus, who was obliged to abandon Asia Minor and take refuge in Egypt. Seleucus undertook an expedition to the East, with the view of reducing the revolted provinces of Parthia and Bactria, which had availed themselves of the disordered state of the Syrian Empire to throw off its yoke. He was, however, defeated by Arsaces, king of Parthia, in a great battle, which was long after celebrated by the Parthians as the foundation of their independence. After the expulsion of Antiochus, Attalus, king of Pergamus, extended his dominions over the greater part of Asia Minor; and Seleucus appears to have been engaged in an expedition for the recovery of these provinces, when he was accidentally killed by a fall from his horse, in the twenty-first year of his reign, 226. He left two sons, who successively ascended the throne, Seleucus Ceraunus and Antiochus, afterward surnamed the Great. His own surname of Callinicus was probably assumed after his recovery of the provinces that had been overrun by Ptolemy.