Cycnus

Half-divine son of Poseidon by a mortal mother (Calyce, Scamandrodice, Harpale, or Phylonome across competing variants); king of Colonae in the Troad; first significant Trojan-side casualty in the Greek landing before Troy. The divine endowment of invulnerability to ordinary weapons constrains the killing-method to non-piercing improvisation — Achilles strangles him with his helmet-strap in the dominant Ovidian tradition. Transformed into a swan at the moment of death per Ovid, the eponymous-bird metamorphosis honoring the swan-name. Distinct from the other Cycnus figures in Greek myth: Cycnus son of Ares (killed by Heracles, treated in Hesiod's Shield), Cycnus son of Apollo and Thyrie (the swan-eponym narrative in Antoninus Liberalis 12), and the Ligurian Cycnus mourning-friend of Phaethon — all separate figures sharing only the bird-name.

Parentage

• paternal: Poseidon

Children

• Tenes

Variant accounts

• maternity-variant
• maternity-variant

Domains

• invulnerability to ordinary weapons

Powers

• Be transformed by Poseidon into a swan at death
• Be invulnerable to blade and spear

Relations

• sibling: OrionFull sibling; shares the same complete attested parentage.
• father of: Tenes (eponym of Tenedos) · GreekApollod. Epit. 3.23-26; Paus. 10.14.1-4 (primary)
• father of: Hemithea · GreekApollod. Epit. 3.23-26 (primary)
• killed by: Achilles (greatest of the Greek warriors at Troy, son of Peleus and the Nereid Thetis; not registered as cascade descendant under strict rule) · GreekCypria fr.; Apollod. Epit. 3.31; Ov. Met. 12.64-145 (primary)

Sources

• existence: Cypria fragments (via Proclus Chrestomathia); Apollodorus Epitome 3.23-26, 3.31; Pindar Olympian 2.81-83; Hesiod Catalogue of Women fr. 237; Ovid Metamorphoses 12.64-145; Hyginus Fabulae 157; Pausanias 10.14.1-4; Euripides fr. 376 (primary)
• parentage: Apollod. Epit. 3.31; Pind. Ol. 2.81-83 (primary)