The mission system was developed as a method to occupy lands that might otherwise become occupied by the Russians, the English, or the French. The missions were operated by the padres, but guarded by soldiers.
Spain built the California missions.
In California, a total of 21 Missions were built. See link:
Spain.
21
He built 9 missions in California.
many people think the spanish did but some think american indians did
Fathers Serra, Palou and Parron built the first mission
The Spain people discovered Alta (upper) California where the missions are now and they didn't want anyone to claim their land so they built missions to protect Alta California.
The Spanish government, in conjunction with the Roman Catholic Church, built the missions as a way to subdue the native inhabitants of California.
The coast, so missionaries could get in and out if the country eaisily,
21 missions were built.
The California missions are state historical property and open for services and visitors. They are a part of our history and where they were built cities started around them that still exists today.