Poseidon rescues Aeneas in the middle of his battle with Achilles precisely because, as the god himself says, “it is destined” (morimon: XX 302) that Aeneas must not die at this point.
Nagy argues that Poseidon’s intervention on behalf of Aeneas reflects an independent epic tradition in which the Aeneadae are fated to survive and rule Troy, structurally distinguishing Aeneas’s destiny from the doomed line of Priam.
, The Best of the Achaeans: Concepts of the Hero in Archaic Greek Poetry, 1979thesis