On July 16, 1769, Father Junipero Serra founded the Mission San Diego, the first mission in California. From the article:
"Mission Basilica San Diego de Alcalá was the first of 21 Franciscan missions established in California. Located in present-day San Diego, it was founded on July 16, 1769, by Spanish Friar Junípero Serra in an area long inhabited by the Kumeyaay people. Today the mission site is a National Historic Landmark and continues to be an active Catholic Church.
Before the Spanish exploration of southern California, native peoples known as the Kumeyaay populated the area. By the late 1700s, Spain ventured into their territory in order to expand Spanish land holdings north of Mexico. A religious mission that sought to bring Catholicism to the thousands of natives who called the western coast their home accompanied this political move.
On July 1, 1769, a Franciscan friar, Father Junípero Serra, and a Spanish Capitan, Don Caspar de Portola, founded the first Spanish colony, Presidio, and church in the area. On July 16, Father Serra established the Mission San Diego de Alcalá, a crude church meant to serve both the Spanish colonists and begin Catholic outreach to local natives. The buildings first sat on Presidio Hill. The mission and the surrounding area were named for the Catholic Didacus of Alcalá, a Spaniard more commonly known as San Diego.
The mission remained at its original site for only five years, after which Father Serra moved it six miles to the east. The strong military presence at the San Diego Presidio seemed to deter the native people Serra was trying to reach, and water supplies were insufficient for the church’s agricultural ventures. The mission site was then moved to a valley several miles to the east, which was an ideal location close to both the San Diego River and many of the native villages along it. A wooden church and outbuildings were constructed in 1774.
Almost immediately there was a noticeable increase in the number of conversions which, by 1775, stood at 431. However, some of the local Kumeyaay people resented the Spanish intrusion into their land and in the early morning hours of November 4, 1775, more than 600 warriors silently crept into the mission compound. After plundering the chapel, they set the other buildings on fire which soon awakened the two missionaries, the Spanish guards, and the Christian neophytes."