The California missions were a series of religious and military outposts established by Franciscan friars in the 18th century. The purpose of the missions was to spread Christianity and Spanish culture throughout the region. They also served to create a buffer between Spanish settlements and Native American populations, as well as to provide a source of revenue for the Spanish crown. In addition to religious and military functions, the missions also provided social services to the local population, such as medical care and education. Today, the missions are a reminder of California's rich and varied history, and serve as popular tourist attractions.