Haemus

In Greek mythology, King Haemus (or Haimos) of Thrace was the son of Boreas. He was vain and haughty and compared himself and his wife, Queen Rhodope, to Zeus and Hera. They changed him and his wife into mountains (Haemus Mons and Rhodope Mountains, respectively). In Greek, the Balkan Peninsula was thus known as the Peninsula of Haemus (Χερσόνησος του Αίμου). This naming of the Balkans has some basis amongst today Greeks as well.
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[Greek] The son of King Boreas of Thrace. In his vanity he compared himself and his wife Rhodope with Zeus and Hera. Zeus punished them by turning them into mountain with the same name (the current Balkan).