|Parents||Ares and Aphrodite|
|Names||Lady of civil unity|
|Titles||Goddess of harmonia|
Harmonia is the goddess of harmony.
Harmonia was the daughter of Ares and Aphrodite and was closely allied to Aphrodite, as the love that unites all people. She became the wife of Cadmus, and by him became the mother of Ino, Polydorus, Autonoë, Agave and Semele. Their youngest son was Illyrius.
Those who described Harmonia as a Samothracian related that Cadmus, on his voyage to Samothrace, after being initiated in the mysteries, perceived Harmonia, and carried her off with the assistance of Athena. Harmonia accompanied Cadmus when he left Thebes. When they came to the Encheleans, they assisted them in their war against the Illyrians, and conquered the enemy. Cadmus then became king of the Illyrians, but afterwards he was turned into a serpent. Harmonia, in her grief, begged the gods to spare him, and they granted her wish. Before the death of her husband she made him immortal.
When the government of Thebes was bestowed upon Cadmus by Athena, Zeus introduced Harmonia to him. All the gods honored the wedding with their presence.
On their wedding day, Cadmus presented the bride with a robe and a fatal necklace, which he had received from Hephaestus. This necklace, commonly referred to as the Necklace of Harmonia, brought misfortune to all who possessed it. It brought suffering and misfortune to her own children: Semele, Agave and Ino.Polyneices, who inherited the necklace, gave it to Eriphyle, that she might persuade her husband, Amphiaraus, to undertake the expedition against Thebes. Through Alcmaeon, the son of Eriphyle, the necklace came into the hands of Arsinoe, next into those of the sons of Phegeus, Pronous and Agenor, and lastly into those of the sons of Alcmaeon, Amphoterus and Acarnan, who dedicated it in the temple of Athena Pronoea at Delphi.
The necklace had brought mischief to all who had been in possession of it, and it continued to do so even after it was dedicated at Delphi. Phayllus, the tyrant, stole it from the temple to gratify his mistress, the wife of Ariston. She wore it for a time, but at last her youngest son was seized with madness, and set fire to the house, in which she perished with all her treasures.