<P> Apollo aided Paris in the killing of Achilles by guiding the arrow of his bow into Achilles' heel . One interpretation of his motive is that it was in revenge for Achilles' sacrilege in murdering Troilus, the god's own son by Hecuba, on the very altar of the god's own temple . </P> <P> When Zeus struck down Apollo's son Asclepius with a lightning bolt for resurrecting Hippolytus from the dead (transgressing Themis by stealing Hades's subjects), Apollo in revenge killed the Cyclopes, who had fashioned the bolt for Zeus . Apollo would have been banished to Tartarus forever for this, but was instead sentenced to one year of hard labor, due to the intercession of his mother, Leto . During this time he served as shepherd for King Admetus of Pherae in Thessaly . Admetus treated Apollo well, and, in return, the god conferred great benefits on Admetus . </P> <P> Apollo helped Admetus win Alcestis, the daughter of King Pelias and later convinced the Fates to let Admetus live past his time, if another took his place . But when it came time for Admetus to die, his parents, whom he had assumed would gladly die for him, refused to cooperate . Instead, Alcestis took his place, but Heracles managed to "persuade" Thanatos, the god of death, to return her to the world of the living . </P> <P> Niobe, the queen of Thebes and wife of Amphion, boasted of her superiority to Leto because she had fourteen children (Niobids), seven male and seven female, while Leto had only two . Apollo killed her sons, and Artemis her daughters . Apollo and Artemis used poisoned arrows to kill them, though according to some versions of the myth, a number of the Niobids were spared (Chloris, usually). Amphion, at the sight of his dead sons, either killed himself or was killed by Apollo after swearing revenge . </P>

Why is apollo the patron god of delphi