Andromachus (Greek: Aνδρoμαχoς, lived 3rd century BC) was an Anatolian nobleman of Greek Macedonian and Persian descent. Andromachus’ father was a wealthy nobleman who owned estates in Anatolia and his family had power in Anatolia with strong royal connections. Andromachus was the second son of Achaeus by an unnamed Greek mother and a grandson of Seleucus I Nicator (the founder of the Seleucid Empire) and his first wife Apama I. He had four siblings; one brother: Alexander and two sisters: Antiochis and Laodice I. He was the father of Achaeus and Laodice II. Laodice II married her cousin, the Seleucid King Seleucus II Callinicus and they were the parents of Antiochus III the Great.
At some moment in the course of a war between the Seleucids and Egyptian Greek Pharaoh Ptolemy III Euergetes took him prisoner; and when Ptolemy III died in 221 BC, Andromachus was still a prisoner in Egypt. Since Achaeus had long shown great anxiety to secure his father's release, Ptolemy IV of Egypt’s chief advisor Sosibius, regarded the captive grandee as a very valuable piece to play in the political game. He had, perhaps, before the revolt of Achaeus, tried to strike a bargain with him-—the release of Andromachus as the price of Achaeus deserting his king. When Achaeus had once revolted, pushed by other circumstances, and without having made any compact with Egypt, there was the less reason to let Andromachus go. Sosibius was very unwilling to part with such a valuable asset; but around 220 BC the Rhodians exerted themselves as intercessors on behalf of Achaeus, changing radically the situation.The Rhodians decision did not spring from altruism: it was a move with which they hoped to defeat the city-state of Byzantium, with which they were at war. Byzantium hoped to gain Achaeus' support against Rhodes and its allies; by obtaining Andromachus release the Rhodians planned to foil this design and obtain Achaeus' benevolence. They therefore sent an embassy to Ptolemy IV asking him to deliver this Andromachus to them; this request they had before made, but without laying any great stress upon it. Now, however, they put much more insistence upon it; and while Ptolemy at first refused to free Andromachus, on second thoughts, being anxious to please the Rhodians, the king yielded to their request, and handed over Andromachus to them to conduct to his son. This was done, and father and son were reunited. After this occurrence, Andromachus disappears from history. Notes ^ Grainger, A Seleukid prosopography and gazetteer p.8 ^ Billows, Kings and colonists: aspects of Macedonian imperialism p.110 ^ Billows, Kings and colonists: aspects of Macedonian imperialism p.110 ^ Polybius, iv. 51, viii. 22 ^ Polybius, iv. 51