When the spanish frontier expanded Northward from central Mexico, the presidio, the mission, and the civil settlement became related frontier institutions for supporting spanish colonization. Spanish missions generally were accompanied by presidios. Martin Enriquez, fourth viceroy of New Spain (1568-80), is generally credited with originating the presidios of the Southwest. He orderd the construction along the main road from Mexico City north to Zacatecas of casas fueres ("fortified houses"). The pattern of the early presidios was learned from the Moors and dated from the days of the reconquest in Spain.