"the pur that roared from the towers of Ilion and screamed on that desolate, windy beach, from the funeral pyre of Patroklos"
This refers to events from the Trojan War, as told in Homer's epic poem; Ilion being a Greek word for Troy (hence Iliad).
Patroklos was Achilles' close friend and comrade-at-arms during the Trojan War; some sources hold that they were lovers. His death in battle is one of the turning points of the Iliad,
the event that draws Achilles back into combat.