The so-called “Boreads” or “Boreadae” were Calais and Zetes, twin sons of Boreas, the god of the North Wind, and his Athenian wife Orithyia. As sons of the North Wind, the Boreads were winged and had the power of flight.
The Boreads travelled from their father’s home in Thrace to join the Argonauts on their quest for the Golden Fleece. During the voyage, the Boreads were known for chasing the Harpies away from the blind prophet Phineus (at least in the standard account). They were later killed on the island of Tenos by Heracles, who considered them responsible for his abandonment by the Argonauts.