Skip to main content
Greek Mythology Notes

Cycnus of Troy

🗡 heroΚύκνος
invulnerability

Son of Poseidon who was invulnerable to weapons and fought Achilles on the beach at Troy until stran‌​‌​‍​‌​‍​‍​‌​‍​‍​‌​‌​‌​‌​‌​‍​‍​‍​‍​‌​‍​‍​‌​‍​‍​‍​‌​‌​‍​‌​‌​‍​‍gled with his own helmet strap.

The Legend of Cycnus of Troy

No weapon could pierce his skin — so Achilles strangled him with the strap of his own helmet.‌​‌​‍​‌​‍​‍​‌​‍​‍​‌​‌​‌​‌​‌​‍​‍​‍​‍​‌​‍​‍​‌​‍​‍​‍​‌​‌​‍​‌​‌​‍​‍ Cycnus, son of Poseidon, defended the Trojan beach when the Greeks landed. Arrows bounced off him. Spears shattered. Achilles threw everything he had and nothing worked. Finally, Achilles tackled Cycnus and throttled him with his helmet chinstrap, the one part of his equipment that was not divine. As he died, Poseidon transformed him into a swan (kyknos). The fight established Achilles's dominance immediately upon arrival — even an invulnerable opponent could not survive him. It also foreshadowed Achilles's own vulnerability: the greatest warrior had his own fatal weak point.

Parents

Poseidon

Symbols

swanhelmet strapimpervious skin

Fun Fact

Cycnus (swan) gives us the constellation Cygnus and the concept of a swan song.

Words We Inherited

English words and phrases that trace back to this myth. See our full guide to English words from Greek mythology.

cygnus

Explore Further

Achilles

🗡 hero

Greatest warrior of the Trojan War

The greatest warrior in the Greek army at Troy, nearly invulnerable thanks to being dipped in the River Styx as an infant — except for the heel by which his mother held him.

Achilles heelAchilles tendon

Ajax

🗡 hero

The immovable warrior who held the Greek line

The massive warrior from Salamis who carried a shield like a tower wall and held the Greek line when every other defender broke.

Ajax the Lesser

🗡 hero

Swift warrior of the Locrians

Ajax son of Oileus was a fast, fierce, impious warrior whose assault on Cassandra in Athena's temple brought divine wrath upon the Greek fleet.

ajax

Perseus

🗡 hero

Hero who slew Medusa

The son of Zeus and Danae who beheaded Medusa, rescued Andromeda, and founded the Perseid dynasty of Mycenae.

Achilles

🗡 hero

The greatest warrior of the Trojan War

The swift-footed son of Peleus and Thetis whose wrath drives the Iliad and whose choice between glory and life defines the heroic ideal.

Achilles heelAchilles tendon

Euphorbus

🗡 hero

Combat, beauty

Trojan warrior famed for his beauty who first wounded Patroclus before Hector delivered the killing blow

Tydeus

🗡 hero

The ferocious warrior who forfeited immortality

A hero of savage courage who fought as one of the Seven Against Thebes but lost Athena's gift of immortality in his final moment.

Hippomedon

🗡 hero

None recorded

One of the Seven against Thebes, a towering warrior known for his ferocity in battle

Sarpédon

🗡 hero

Son of Zeus who died at Troy

Sarpedon was a son of Zeus and the greatest Lycian warrior at Troy — his death forced Zeus to confront the limits of even divine power.

Graphium sarpedon (blue triangle butterfly)

Ajax the Great

🗡 hero

Mightiest Greek warrior after Achilles

Ajax son of Telamon was the tallest and strongest of the Greek warriors at Troy, a tower of a man who fought with a massive shield and never received divine aid.

ajax

Caenus

🗡 hero

Transformation, Invulnerability, Gender

Lapith warrior transformed from a woman into an invulnerable man by Poseidon, killed by Centaurs pounding him into the earth.

Bellerophon and Pegasus

🗡 hero

hubris, fall

The hero who tamed Pegasus and slew the Chimera but was destroyed by his own hubris when he tried to fly to Olympus.

chimerachimericalbellerophon