A contemporary observer of the four-year Tepehuan Indian revolt in a northern province of New Spain described it as "one of the greatest outbreaks of disorder, upheaval, and destruction that had been seen in New Spain since the Conquest".In The Tepehuan Revolt of 1616, Charlotte Gradie presents the uprising as a pivotal test of both the Spanish institutions of conquest and Jesuit evangelism, as well as the Tepehuan capacity for military and cultural resistance. The unrest resulted in the death of over two hundred Spaniards, along with an uncounted number of slaves and servants. Ten missionaries, eight of them Jesuits, also died, and there was massive destruction of property. The number of Tepehuanes who died from war-related causes was estimated by one Spanish source at 4,000.The horror of the uprising for the Spanish was enhanced by its total surprise. The Tepehuanes, considered "pacified" since 1590, were known for their bellicosity, but by the time of the uprising many had settled in mission towns supervised by Jesuits who spoke the native language. For the Spanish, the only logical explanation was that the Tepehuanes' revolt was the work of the devil. Although the Spanish policy toward indigenous peoples had evolved from one of total war to one that relied on the more peaceful missions, the revolt caused the Spanish to reintroduce the presidio system to protect the missions and the labor source for their expanding economy.While the ultimately unsuccessful revolt may have been an effort by Tepehuan warrior elite to reassert their authority, it resulted in a reaffirmation of Jesuit missionary activity in Mexico and altered Spanish colonial methods in Sinaloa, Sonora, BajaCalifornia, and Arizona.