In the Trojan War tradition, Achilles was the father of Neoptolemus.
Neoptolemus was the son of Achilles and Deidamia, daughter of King Lycomedes of Scyros. He was also called Pyrrhus, a name especially common in later Greek and Roman accounts. Because Achilles died before Troy was captured, the Greeks brought Neoptolemus to the war to fulfill a prophecy that Troy could not fall without a descendant of Aeacus fighting there.
Neoptolemus joined the Greeks late in the conflict and became known for his ferocity. Later traditions credit him with killing Priam during the sack of Troy and with helping enter the city through the wooden horse, although the details vary among sources.
After the war, Neoptolemus received Andromache, Hector’s widow, as a captive. His story continues in myths involving Hermione, Orestes, and the sanctuary at Delphi.