In 1542 Juan Rodríguez Cabrillo, a Portuguese navigator sailing under the flag of Spain, arrived in the harbor and named the area San Miguel in observance of the Feast Day of Saint Michael the Archangel. In 1602 Sebastián Viscanio, sailing aboard the flagship San Diego, dropped anchor and named the area San Diego after Saint Didacus of Alcalá, Spain. In 1768, fearing Russian encroachment, King Carlos III of Spain instructed Viceroy José de Gálvez of New Spain to establish settlements along the coast of Alta California to claim the land for Spain. Because Gálvez wanted the plan's motives to appear religious rather than political, he chose the Franciscan order of Catholic priests led by Padre Junipero Serra to accompany the military and take responsibility for converting the native population to Christianity. In 1769, four expeditions were sent out, two by land and two by sea, including the San Carlos and San Antonio. On July 16, 1769, Mission San Diego de Alcalá was founded on a site overlooking the bay as the first mission in Alta California. In 1774, the mission was moved to its present site to be closer to the American Indian population, a better source of water, and more fertile soil.