Cabrillo, Juan Rodríguez (hwän rôħrēˈgāth käbrēˈlyō) [key], Port. João Rodrigues Cabrilho, d. 1543, Spanish conquistador and discoverer of California, b. Portugal. In 1520 he landed in Mexico with Pánfilo de Narváez and joined in the conquests of Mexico and Guatemala. Accompanying Pedro de Alvarado up the west coast of Mexico, he assumed command of the expedition and continued the voyage after Alvarado's death. He discovered San Diego Bay on Sept. 28, 1542, landing at Point Loma Head, now in Cabrillo National Monument. He then sailed on to Northwest Cape beyond San Francisco Bay, which he did not find. Returning to winter on San Miguel Island off the Santa Barbara coast, he died Jan. 3, 1543.