Southern California was first observed by Europeans in the fourteenth century. In 1542, Captain Juan Rodriguez Cabrillo apparently "discovered" California. The purpose of Cabrillo's expedition was to sail the coastline of California in search of a new route to Asia. Beginning from his base at Navidad, Mexico, Cabrillo's two small galleons, the San Salvador and the Victoria sailed north from the coast of Baja California in early October of 1542 and stopped at a natural port which they named San Miguel and later renamed San Diego. They continued north and observed the islands of San Clemente and Santa Catalina, as well as the shoreline of a bay (probably Santa Monica).
Sixty years after Cabrillo, in May, 1602 Captain Sebastian Vizcaíno set sail from Alcapulco along Cabrillo's route. Vizcaíno's mission was to explore the California coast and to search for possible ports for the use of large ships known as the Manila Galleons, which traded goods between Acapulco and the Philippines from 1566 to 1821. These ships needed protection from the ongoing raids of English and Dutch pirates along the coast of Mexico and South America. In the Spanish period the two parts of California were known as Baja and Alta California. The colonization of Alta California was resumed in the eighteenth century under Visitador General José de Galvez. Galvez' basic plan for the occupation of Alta California would be enacted in 1769 by a joint land-sea expedition, consisting of two land and two sea parties. The primary objective of the expedition was to rediscover and occupy the port of Monterey, which had been discovered by Vizcaíno in 1602, and secondarily to establish new missions and presidios there and at San Diego. To lead the expedition, Galvez selected Lt. Colonel Gaspar de Portolá, the newly appointed Governor of Baja California, and Father Junípero Serra, the Franciscan head of the former Jesuit missions of Baja California. It was during the land expedition from San Diego to Monterey that the Los Angeles region was first examined at close range. Father Juan Crespí and Engineer Miguel Costansó, who accompanied Portolá north from San Diego were among the principal diarists of the 1769 expedition. Both took careful note of the landscape and the native population as the Portolá party passed very near the site where the Pueblo of Los Angeles would be founded in 1781. In 1774 and 1776, Captain Juan Bautista De Anza led two expeditions which brought settlers from Sonora, Mexico to Alta California. The groups stopped at Mission San Gabriel and Los Angeles before making their way north to the San Francisco Bay, a journey of 1,200 miles. Diaries of these expeditions provide vivid descriptions of the native inhabitants and natural surroundings of California.