The Trojan War begins when Paris, a prince of Troy, kidnaps Helen, the wife of Menelaus from Sparta, and brings her to Troy. Although Helen is influenced by Aphrodite's enchantment, her actions are still seen as a betrayal that the Greeks feel they must avenge. The Iliad intricately explores themes of loyalty and betrayal, categorizing characters as either good or bad, leaving little room for uncertainty.

Achilles remains loyal to Agamemnon only as long as their mutual tolerance lasts. When Agamemnon offends Achilles, Achilles deserts both him and the army. Agamemnon's loyalty is questioned because he chooses to antagonize his mightiest warrior during intense warfare. Paris appears to be loyal only to himself, and Helen leaves with him at least partly of her own accord, albeit influenced by Aphrodite. After Paris dies, Helen doesn't immediately return to Menelaus but marries Deïphobus before eventually returning to Sparta as Menelaus's queen.

Hector and Athena stand out as truly loyal characters. Hector willingly sacrifices his life for his homeland and his father, the king, while Athena steadfastly protects the Greeks. Despite being on opposing sides, these two characters seem to rise above the conflict, suggesting that a simple dialogue between them could unveil the senselessness of the war they are involved in.