Atreus (AY-tree-uhs), the oldest son of Pelops and the rightful ruler of Mycenae. He is the protagonist in what is arguably the most fiendish revenge play in the history of the theater. He and his brother Thyestes were supposed to alternate in ruling Mycenae, but neither of them respected the other’s rights. Having won the latest civil war, Atreus has consolidated his power and is now ready to avenge himself on his brother. Asserting that, as a king, he is not bound by moral law, Atreus formulates his plan. He sends his two sons to Thyestes with a friendly message, inviting him to return to Mycenae and share the throne with Atreus. When Thyestes arrives, Atreus welcomes him warmly; later, however, Atreus kills his nephews, butchers them, cooks the meat, and at a great feast serves it to their unsuspecting father. He concludes by giving Thyestes wine mixed with his children’s blood, then reveals the truth by uncovering a platter holding their heads. Gloating over his brother’s distress, Atreus claims victory. Now, Atreus says, his marriage bed has been cleansed and he can be sure that his sons are his own. He ends by scoffing at the idea that the gods will punish him.

Thyestes (thi-EHS-teez), Atreus’ brother, who seduces his wife and steals the golden ram, the symbol of power in the kingdom. Having been defeated and banished by Atreus, Thyestes accepts with foreboding his brother’s invitation to return to Mycenae. When Atreus insists that he accept a crown, Thyestes believes that his brother really has forgiven him, and he relaxes his guard. At the feast in his honor, Thyestes drinks heavily and enjoys his food, although he has a strange premonition of evil. He is fed the bodies of his sons at the banquet. When Atreus reveals the heads of the dead boys and tells their father that he has consumed his own children, Thyestes can only wish for his own death. Although he deserved to suffer, he says, his sons were innocent, and he calls on the gods to avenge them. His greatest regret is his inability to get similar vengeance on Atreus.

Tantalus (TAN-tuh-luhs), a tragic character, bears the weight of his forebearer's infamous actions. As Thyestes's son and namesake to his great-grandfather, Tantalus plays a crucial albeit brief role. He persuades Thyestes to accept Atreus's deceptive invitation, unaware of their impending doom. Tantalus is the first to fall victim to Atreus's murderous plan, a poignant reminder of the inescapable curse plaguing their lineage.

Thyestes's two other sons, victims of Atreus's elaborate scheme, represent the enduring tragedy of the House of Atreus. Murdered by their uncle, their bodies were heartlessly prepared for the grotesque banquet, further cementing the myth's legacy of familial betrayal and curse.

Megaera (meh-GAY-ruh), one of the formidable Furies in Greek mythology, dictates the course of events in the play by commanding the Ghost of Tantalus. As a goddess of vengeance, she orchestrates the ancestral curse's resurgence, infusing Atreus's reign with malevolence and ensuring his lineage's continued suffering.

Pelops (PEE-lops), Atreus and Thyestes's father, plays a significant ancestral role in the myth. Resurrected by the gods after his father Tantalus's grisly banquet offering, Pelops's legacy is marred by trickery and deceit. His acquisition of Pisa's throne through deception adds another layer to the family's curse, further intertwining their fates with divine retribution and human folly.

Agamemnon (a-guh-MEHM-non) and Menelaus (meh-nuh-LAY-uhs), the sons of Atreus, represent the next generation embroiled in the ongoing saga of the House of Atreus. Their presence signifies the perpetuation of the curse, which extends beyond their father's reign, influencing significant events in Greek mythology, most notably the Trojan War, and appearing in various ancient texts and plays including works by Seneca.