Origin of the Name "Gulf of California"

The naming sequence is often misunderstood. The name "California" originated in a 1510 Spanish romance novel (Las Sergas de Esplandián) describing a mythical island of gold and Amazons. In 1535, Hernán Cortés applied it to the peninsula now called Baja California. The body of water between the peninsula and mainland Mexico was initially called the Sea of Cortés (Mar de Cortés). By the 1700s, the name "Gulf of California" came into use—named after the peninsula/region, not the modern U.S. state (which didn't exist until 1850). So: the peninsula was named California first, then the gulf was named for the peninsula.