The word California originally referred to the entire region composed of what is today the state of California, plus all or parts of Nevada, Utah, Arizona, and Wyoming, and the Mexican peninsula of Baja California.

The name California is most commonly believed to have derived from a fictional paradise peopled by Black Amazons and ruled by Queen Calafia. The story of Calafia is recorded in a 1510 work The Exploits of Esplandian, written as a sequel to Amadís de Gaula by Spanish adventure writer Garci Rodríguez de Montalvo. The kingdom of Queen Calafia, according to Montalvo, was said to be a remote land inhabited by griffins and other strange beasts, and rich in gold.

Know ye that at the right hand of the Indies there is an island called California, very close to that part of the Terrestrial Paradise, which was inhabited by black women without a single man among them, and they lived in the manner of Amazons. They were robust of body with strong passionate hearts and great virtue. The island itself is one of the wildest in the world on account of the bold and craggy rocks.

The name California is the fifth-oldest surviving European place-name in the U.S. and was applied to what is now the southern tip of Baja California as the island of California by a Spanish expedition led by Diego de Becerra and Fortun Ximenez, who landed there in 1533 at the behest of Hernando Cortes.

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