Etymology of California

Multiple theories regarding the origin of the name California, as well as the root language of the term, have been proposed, but most historians believe the name likely originated from a Spanish 16th-century novel, Las sergas de Esplandián. The novel, popular at the time of the Spanish exploration of Mexico and the Baja California Peninsula, describes a fictional island named California, ruled by Queen Calafia, east of the Indies. The author of the novel, Garci Rodríguez de Montalvo, also known as Ordóñez de Montalvo, is thought to have derived the name California from the Arabic Khalif and/or Khalifa, but he may also have been influenced by the place name "Califerne" in the Song of Roland, an 11th-century epic poem written in Old French.

When Spanish explorers in the 16th century first encountered the Baja California Peninsula, west of the Sea of Cortez, they believed the peninsula to be an island similar to the island described in de Montalvo's novel. They named the land California. Initially, California applied only to Baja California Peninsula; however, as Spanish explorers and settlers moved north and inland, the region known as California, or Las Californias, grew. Eventually it included not only the peninsula, but also the lands north of the peninsula, along the coast of today's U.S. state of California. Unlike the peninsula, this region was only practical to reach by sea voyages, and acquired a separate identity: Alta (Upper) California, making the lower territory Baja (Lower) California.

Today, the name California is shared by many places throughout the world, but is most commonly associated with areas of the southwest United States, and northwest Mexico. When used alone, California generally refers to the U.S. state of California, but when paired with the term "baja", or "lower", it can refer to the Baja California Peninsula, or one of the Mexican states on the peninsula, Baja California, or Baja California Sur.