Cycnus

In Greek mythology, multiple characters were known as Cycnus (Κύκνος) or Cygnus. The literal meaning of the name is "swan", and accordingly most of them ended up being transformed into swans.

Cycnus, son of Ares by Pelopia or Pyrene, was a bloodthirsty and cruel man who dwelt either in Pagasae, Thessaly or by the river Echedorus in Macedonia, and killed all of his guests until he was slain by Heracles. According to Pausanias, one of the men murdered by him was Lycus of Thrace.

Pseudo-Apollodorus wrote of Cycnus the Thessalian, the son of Pelopia, and Cycnus the Macedonian, the son of Pyrene, as two distinct encounters of Heracles, mentioning them separately. The Thessalian Cycnus, he relates, challenged Heracles to single combat and was killed by him; the same is recounted by Diodorus. The Macedonian Cycnus, according to the Bibliotheca, also challenged Heracles to single combat; Ares attempted to avenge his son's death, but a thunderbolt was hurled by Zeus between the combatants, causing them to part.

In the poem Shield of Heracles, Heracles and Iolaus encountered Cycnus and Ares on the way to Trachis, each pair riding a chariot; it is mentioned that Heracles was directing to the court of King Ceyx, to whose daughter Themistonoe Cycnus was married. Apollo, whose Pagasaean sanctuary was next to the place where the characters meet, is said to have stirred Heracles up against Cycnus. Athena appeared, telling Heracles that Zeus too had empowered him to defeat Cycnus, and instructed him not to touch his body or take his armor as spoils, but to hit Ares with a spear in an unprotected part of body if he should attack Heracles to avenge Сycnus's death. Heracles and Сycnus then clashed in single combat and Heracles hit Сycnus in the neck with a spear, killing him. Ares was just about to strike a hit at Heracles when Athena blocked his hit, saying that it was not ordained that he should kill the hero. Heracles took this opportunity to wound Ares in the thigh and beat him to the ground, which caused his sons Phobos and Deimos to rescue him and take him back to Mount Olympus. Сycnus was buried by his father-in-law Сeyx and people of the neighboring cities, but his tomb was destroyed during a flood by the will of Apollo.

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