As early as 1542, the area of southern California was recognized as part of the Spanish colonial empire.

On August 2, 1769, the Spanish officer Gaspar de Portola, who served as the first governor of California, arrived in what is now Los Angeles. In 1771, the first missionary headquarters of Mission San Gabriel Arcangel (now on the UNESCO World Heritage List) was built in these areas, probably designed by the Franciscan missionary Junipero Serra.