Before white settlers stampeded into California in a quest for gold, an earlier wave of colonizers arrived in the name of God. Beginning in the 18th century, Spanish priests established a series of religious outposts in California in an effort to convert the indigenous population. The first — Mission Basilica San Diego de Alcala — turned 250 this year and was dedicated by Junipero Serra on this week in 1769.

Generations of California fourth graders learned about the missions as tile-and-adobe wonderlands where Franciscan friars lived in harmony with the Native Americans. But there was a darker reality: a catastrophic decline of Indians that some historians have likened to extermination.

Outrages accumulated soon after the Franciscans arrived in San Diego: Native Americans were whipped for participating in a pagan dance, for example, and several indigenous women were raped by Spanish soldiers. After six years of tensions, Kumeyaay warriors surrounded the mission, set it aflame, and killed three Spaniards, including a priest. The offensive was ultimately thwarted. But had it prevailed, the historian George Yagi Jr. wrote, it could have inspired a broader revolt that imperiled the entire Spanish project.

As it happened, the Franciscans went on to string a total of 21 missions along the Pacific coast like rosary beads, laying the foundations for California as we now know it.

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