Aidoneus (Gr. Ἀїδωνεύς) was a mythical king of the Molossians in Epirus, who is represented as the husband of Persephone. After Theseus, with the assistance of Pirithous, had carried off Helen and concealed her at Aphidnae, he went to Epirus to procure for Pirithous Kore, the daughter of Aidoneus, as a reward. This king thinking the two strangers were well-meaning suitors, offered the hand of his daughter to Pirithous, on condition that he should fight and conquer his dog, which bore the name of Cerberus. But when Aidoneus discovered that they had come with the intention of carrying off his daughter, he had Pirithous killed by Cerberus, and kept Theseus in captivity, who was afterwards released at the request of Heracles. Eusebius calls the wife of Aidoneus a daughter of queen Demeter, with whom he had eloped. It is clear that the story about Aidoneus is nothing but the sacred legend of Hades' rape of Persephone, dressed up in the form of a real-world history, and is undoubtedly the work of a late interpreter, or rather destroyer, of genuine ancient myths.
This article incorporates text from a publication now in the public domain: Smith, William, ed. (1870). "article name needed". Dictionary of Greek and Roman Biography and Mythology.