The Boreads, in Greek mythology, were Calaïs (Κάλαϊς) and Zetes (also Zethes) (Ζήτης). They were the sons of Boreas and Oreithyia, daughter of King Erechtheus of Athens. Due to being sons of the north wind they were supernaturally gifted in different ways (depending on changes in the story from being passed down through generations and cultures) either being as fast as the wind or able to fly, having wings either on their feet or backs, depending on the myth.
They were Argonauts and played a particularly vital role in the rescue of Phineus from the harpies. They succeeded in driving the monsters away but did not kill them, at a request from the goddess of the rainbow, Iris, who promised that Phineas would not be bothered by the harpies again. As thanks, Phineas told the Argonauts how to pass the Symplegades. It is said that the Boreads were turned back by Iris at the Strophades. The islands' name, meaning "Islands of Turning", refers to this event.
Their death was said to be caused by Heracles on Tenos in revenge for when they convinced the Argonauts to leave him behind as he searched for Hylas.
Other sources imply that the sons of Boreas died chasing the harpies, as it was fated that they would perish if they failed to catch those they pursued. In some versions, the harpies drop into the sea from exhaustion, and so their pursuers fall as well.