Between 1769 and 1823, Spanish Franciscan missionaries established 21 missions along Alta California's coast, from San Diego to Sonoma. They were the vanguard of Spain's northern frontier strategy: claim territory, convert Native peoples, create self-sustaining agricultural communities loyal to the Crown.
Each mission centered on a church, surrounded by workshops, storerooms, soldiers' quarters (presidio), and vast lands worked by Native Californian neophytes—often forcibly relocated, subjected to European diseases, labor regimes, and cultural suppression. Crops: wheat, barley, corn, grapes, olives. Livestock: cattle, sheep, horses. Industries: tanning, weaving, winemaking, blacksmithing.
Junípero Serra founded the first nine (San Diego de Alcalá to San Buenaventura). Fermín Lasuén added nine more. Mariano Payeras and others completed the chain.
Secularized by Mexico (1834), mission lands became ranchos. Native populations collapsed—from ~300,000 pre-contact to ~15,000 by 1900. Today, missions are state parks, parish churches, and contested memory sites: symbols of faith and colonization, architecture and erasure.