Achilles returns to battle in The Iliad primarily due to his deep grief over the death of his close friend Patroclus, who is killed by Hector, the Trojan prince. Initially, Achilles had withdrawn from the conflict because of a personal slight by Agamemnon, the leader of the Greek army. He was angry and felt dishonored, leading him to refuse to fight. However, the loss of Patroclus is a turning point for Achilles.
When Patroclus dies while wearing Achilles’ armor, it intensifies Achilles’ feelings of rage and sorrow. He is driven by a desire for vengeance and to honor his friend’s memory. The moment he learns about Patroclus’ death, Achilles is filled with grief and regret about his previous decision to stay away from the battlefield. This powerful emotional response ignites his rage towards Hector, ultimately compelling him to return to the fight.
Achilles’ return signifies not only a personal journey of loss and revenge but also reflects the themes of honor and the tragic costs of war, central to the narrative of The Iliad. His decision to enter the battle again highlights the complex interplay of personal relationships, honor, and the harsh realities of the battlefield.