Son of Theiodamas, king of the Dryiopians, whom
Heracles killed in a fit of drunkeness. When
Heracles recovered he fell in love with the beautiful Hylas and took him to his household. Hylas was
Heracles' lover and companion for many years, and participated in many of his great adventures, including the voyage over the
Argo.
When the Argonauts landed in Cios, Hylas was sent to fetch water from a near-by spring, but there a water nymph, seeing his great beauty, kidnapped and enspelled him and hidden him within the spring.
Heracles and Polyphemus (not the cyclops) looked for him desperately, and Heracles was so heartbroken that he missed the sail of the Argo.