Echemus became king of the Arcadians on the death of Lycurgus.

He defended the Peloponnese against the Dorians or Heraclides. He agreed to fight Hyllus, the Heraclides' leader, in single combat: if Echemus were to win then the Heraclids would not invade the Peloponese again for fifty or a hundred years. He killed Hyllus and the Heraclids withdrew.

It is said that he was the winner in wrestling in the first Olympian games.

Another account says he participated in the expedition against Attica to release Helen from Thesseus.

Anaea Echemus is the scientific name for a butterfly in North America.
Its common name is Chestnut Leafwing