In Greek mythology, Harmonia (Ancient Greek Ἁρμονία, "harmony," "agreement") is the goddess of harmony and concord. Her Greek opposite is Eris and her Roman counterpart Concordia. She is best known as the bride of Cadmus, founder of Thebes, and for the cursed necklace and peplos that brought misfortune to their descendants through the Theban royal house and beyond.
Adapted from Wikipedia, "Harmonia (mythology)" · CC BY-SA 4.0
I.Family
Harmonia's parentage varies. Most often she is the daughter of Ares and Aphrodite, sister to figures such as Phobos and Eros (and, in some genealogies, linked to Aeneas's line through Aphrodite). In another tradition she was born on Samothrace to Zeus and the Pleiad Electra, sister of Dardanus and Iasion, founders of mystic rites on the island.
In nearly all accounts she marries Cadmus. Their children include Autonoë, Agave, Ino, Semele, Polydorus, and in some accounts Illyrius. Through Semele she is grandmother of Dionysus.
II.Marriage to Cadmus
How Cadmus acquired Harmonia depends on the parentage tradition. In the Samothracian version he receives or carries her off after initiation into the island's mysteries. In the Theban version Zeus gifts her to Cadmus after the founding of Thebes and Cadmus's eight-year service to Ares for slaying the god's sacred dragon.
Their wedding was attended by all the gods. Bridal gifts included a peplos and a necklace (ὅρμος) wrought by Hephaestus. Many tellings say Hephaestus forged the necklace in anger at Aphrodite's affair with Ares, vowing to curse children of that union; other traditions credit Athena, Aphrodite, or Europa (who had received the gifts from Zeus). Hyginus instead blames a peplos "dipped in crime" given by Hephaestus and Hera. The Necklace of Harmonia (also called the Necklace of Eriphyle) brought misfortune to queens and princesses of Thebes and later owners; it is usually described as gold inlaid with jewels such as emeralds.
III.Illyria and the serpent transformation
When Cadmus was expelled from Thebes, Harmonia went with him to Illyria, where they fought for the Enchelii and Cadmus became king. After he wished for a serpent's life and began to change, Harmonia stripped herself and begged to share his fate; the gods transformed her as well and sent the pair to Elysium.
Harmonia was associated with Aphrodite Pandemos — the aspect of Aphrodite that personified civic order and unity — and with the Roman Concordia.
IV.The cursed necklace
All of Cadmus and Harmonia's children suffered great misfortune. Through Agave's son Pentheus the necklace later reached Jocasta; Polynices used the necklace and peplos to bribe Eriphyle into sending Amphiaraus against Thebes. After Amphiaraus's death, Alcmaeon killed Eriphyle, and the objects passed through Alphesiboea and the house of Phegus before Alcmaeon's sons dedicated the necklace at Athena's temple in Delphi. It was later stolen by the Phocian general Phayllus for his mistress; her house burned when her youngest son went mad, and she perished with her treasures.