Caenis, the daughter of Elatus (a Lapith chieftain) and Hippea, was raped by Poseidon, who then fulfilled her request to be changed into a man so that she could never be raped again; he also made Caenis invulnerable to weaponry. Caenis then changed his name to Caeneus and became a warrior, traveling all over Thessaly, and later taking part in the hunt for the Calydonian Boar.
He met his fate in the battle between the Lapiths and the centaurs (see Pirithous). In one description of the tale, a particular centaur, Latreus, mocks Caeneus and denies his skill as a fighter when he realizes Caeneus' female origin. Caeneus strikes Latreus a blow in the side, and is unharmed by the centaur's last attempts at wounding him. In revenge for this, the centaurs piled pine-tree trunks (some say fir trees) and stones upon him since he was immune to weapons.
There are several descriptions of Caeneus' fate after he had been crushed down by the trunks. One vase, for instance, depicts him as sinking down into the earth, upright, and buried at the waist; this legend is described in the Metamorphoses as well, and implies that Caeneus is falling directly into Tartarus. In that same poem another story is presented, which states that Caeneus flew away from the pile of tree trunks as a tawny-winged bird. This version of the ending has two witnesses, Mopsus and the "son of Ampycus", as well as Nestor, who tells the story. Alternatively, he changed back into a woman after death and was buried as a female.
Caenis/Caeneus' legend is found in the Metamorphoses, where he is mentioned briefly as a participant in the hunt for the Calydonian Boar. A while after this appearance, Nestor tells the story of Caeneus to Achilles in fuller detail, describing his transformation from female to male, the story of the battle of the centaurs, and Caeneus' eventual mysterious death.
Similarly, in the Iliad (without referring to these transformations) Nestor numbers Caeneus among an earlier generation of heroes of his youth, "the strongest men that Earth has bred, the strongest men against the strongest enemies, a savage mountain-dwelling tribe whom they utterly destroyed." No trace of such an oral tradition, which Homer's listeners would have recognized in Nestor's allusion, survived in literary epic.
Virgil also says that Aeneus sees her/him in the Fields of Mourning as he visits the underworld in Book Six of the Aeneid. Caeneus has by now been turned back by Fate into her original female form. He was also mentioned in the Catalogue of Women. Caeneus had one son, Coronus.
- Ovid, Metamorphoses VIII, 305; XII, 171-209 & 459-525; Apollodorus, Epitome I, 22; Homer, Iliad, I, 262-8; Virgil, Aeneid VI, 448.
- Ernest Gardner (1897). "Caeneus and the Centaurs: A Vase at Harrow". The Journal of Hellenic Studies 17: 294–305. doi: .