Parthenius of Nicaea was a Greek grammarian and poet who flourished in Rome in the first century BCE. He was the Greek tutor of the poet Virgil. Parthenius’ only surviving work is Erotica Pathemata (Love Stories), texts collected from a variety of Classical and Hellenistic Greek writers. Geryones was supposed to have lived in Spain; Herakles’s taking of his cattle was supposed to have been one of his twelve labours.
The following is an adaptation of Longus, Daphnis and Chloe. Parthenius, Love Romances, trans. J. M. Edmonds and S. Gaselee. Cambridge: Harvard University Press, 1916.
§ 30. Herakles, it is told, after he had taken the cattle of Geryones from Erutheia, was wandering through the country of the Keltoi and came to the house of Bretannos, who had a daughter called Keltinē. Keltinē fell in love with Herakles and hid away the cattle, refusing to give them back to him unless he would first content her. Herakles was indeed very anxious to bring the cattle safe home, but he was far more struck by the girl’s exceeding beauty, and consented to her wishes; and then, when the time had come round, a son called Keltos was born to them, from whom the Keltoi derived their name.