Being the youngest of the Greek warriors at that time, Neoptolemus' behavior was also the most savage and cruelest among them, often being contrasted to Achilles. Among those he killed in the war were the courageous King Priam, his youngest daughter Polyxena, and Hector's son Astyanax. After the fall of Troy, he took Hector's widow, Andromache, as a concubine and sailed to the Epirot Islands with Phoenix and Helenus. He became the king of Epirus who condemned Odysseus to exile after the latter slayed the large number of suitors at his house. Neoptolemus had a son named Molossus from Andromache, and he is also said to have a daughter, Olympias, who later became the mother of Alexander the Great.
Eventually, Neoptolemus met his death either after he later robbed Hermione from her husband Orestes, or after he tried to claim satisfaction from the death of Achilles to the god who killed the hero, Apollo. In either case, Orestes murdered him in Apollo's temple at Delphi, but some say it was a Delphian cult of Apollo who killed him.