The Spanish missions in Baja California were a large number of religious outposts established by Catholic religious orders, the Jesuits, the Franciscans and the Dominicans, between 1683 and 1834 to spread the Christian doctrine among the Native Americans or Indians living on the Baja California peninsula. The missions gave Spain a valuable toehold in the frontier land, and introduced European livestock, fruits, vegetables, and industry into the region. The Indians were severely impacted by the introduction of European diseases such as smallpox and measles and by 1800 their numbers were a fraction of what they had been before the arrival of the Spanish.