Achilles is the main protagonist and the most powerful warrior of the Achaeans (Greeks). He is the son of Peleus, the king of Phthia, and Thetis, a sea goddess. His wrath and pride are the main sources of conflict in the poem, as he withdraws from the war after being dishonored by Agamemnon, the leader of the Achaean coalition. His re-entry into the battle after the death of his friend Patroclus leads to the death of Hector, the greatest warrior of the Trojans, and the eventual fall of Troy.
Odysseus is the king of Ithaca and one of the most cunning and resourceful heroes of the Achaeans. He is a master of speech and strategy, and often acts as a mediator and an advisor among the Achaean leaders. He is instrumental in the execution of the Trojan Horse, the decisive ruse that enables the Greeks to breach the walls of Troy. He is the protagonist of another epic poem attributed to Homer, the Odyssey, which narrates his ten-year journey home after the war.
Helen is the daughter of Zeus and Leda, and the most beautiful woman in the world. She was the wife of Menelaus, the king of Sparta, until she was abducted by Paris, the prince of Troy, with the help of Aphrodite, the goddess of love. Her elopement triggered the war between the Greeks and the Trojans. She is portrayed as a complex and conflicted character, who regrets her actions but also feels sympathy for her new husband and his people. She is admired and desired by both sides, but also blamed and scorned for the bloodshed and misery she caused.
Zeus is the king of the gods and the father of many of the major characters in the poem. He is the supreme authority in the divine realm, and his will determines the fate of the mortal world. He is often torn between his allegiance to his wife Hera, who supports the Greeks, and his affection for his son Apollo, who supports the Trojans. He tries to maintain a balance between the two sides, but also intervenes to favor one or the other according to his whims or promises.