Who was the Iliad petitioner?

In the context of Homer's "Iliad," the petitioner is Achilles, the greatest Greek warrior. He appeals to the goddess Thetis, his mother, seeking her help to turn the tide of the war after being dishonored by Agamemnon. Achilles' request sets off a chain of events that significantly impacts the course of the Trojan War. His anger and withdrawal from battle are central themes of the epic.