When the Spanish conquered the Aztec Empire in the early 16th century, the largest indigenous group in the state was the Otomi, many of whom were living more or less under Purépecha rule. This population would increase with Otomi refugees from Aztec lands fleeing the Spanish. Another significant group was the Chichimecas. With the fall of Tenochtitlán, then the Purépecha Empire, the Spanish gained some control over the southern portion of the state. However, the area was still very independent, filled with peoples who lived in small isolated villages or nomadically. There were no major cities, nor large societies there or north.