As an English name, it has been used occasionally since the 12th century. It is the name of a central character in Shakespeare's play The Two Gentlemen of Verona (1594).
As a given name it was mostly masculine in America until around 2009. It was already rising in popularity for girls when singer Mariah Carey gave it to her daughter born 2011 (though this probably helped accelerate it).
This name is also common for girls in Estonia, though a connection to the English-language name is uncertain.
Though it has never been popular in the English-speaking world among Christians, it has historically been a common name for Jews, who have used it as an Americanized form of names such as Isaac, Israel and Isaiah.
In the Centauromachy, Caeneus killed five (named) centaurs: Antimachus, Bromus, Elymus, Pyracmus and Styphelus. Caeneus also engaged in combat with a centaur named Latreus, who knew of Caeneus' birth sex and took offense to his chosen life. Caeneus' spear barely misses Latreus, who then strikes Caeneus in the face with his own, only for the spear to shatter across Caeneus' skin. He attempts again to kill Caeneus with his sword and receives the same results. At this point the story diverges, with some saying that Caeneus kills Latreus with a blow to the side. Others say Latreus was wounded by Caeneus and became enraged, so he instead tried to bury Caeneus under pine or fir trunks so heavy that even Caeneus' immense strength could not free him. Depending on the myth, this results in either Caeneus being buried alive, being pushed through the earth and straight into Tartarus or he instead shape-shifts and flies away as a golden-winged or tawny bird. In the myths where Caeneus kills Latreus, it is instead Monychus who buries Caeneus (albeit with the help of the other centaurs).