With the appearance of the Toltecs and later the Mexica, much of central Mexico again came under unified rule. The Toltecs started to migrate into the area about the eighth century. The name Toltec means in Nahuatl means "master builders." They cane from the arid land of northwestern Mexico, and the settled mostly at Tula, about 50 kilometers northwest of modern-day Mexico City. Though the area had thin soil and little rainfall, the Toltecs tapped the waters of the nearby River Tula to irrigate crops of beans, peppers, maize, chilies, and cotton. From about 950-1150 C.E., at their high point, Tula was said to have supported an urban population that might have reached 60,000 people.
The Toltecs upheld a large and powerful army that campaigned every so often throughout central Mexico. They managed to build a compact regional empire and maintained fortresses far to the northwest to protect their state from invasion by nomadic peoples. From the mid-tenth to the mid-twelfth centuries, they obtained tribute from subject peoples and transformed their capital into a wealthy city. There, residents lived in roomy houses made of adobe, stone, or mud and even sometimes covered their floors with plaster.
Tula became an important center of weaving, pottery, and obsidian work. Residents imported large amounts of jade, turquoise, animal skins, exotic bird feathers, and other luxury goods from other places in Mesoamerica. The Toltecs also kept close connection with other societies on the Gulf coast, as well as with the Maya of Yucatan. Starting at about 1125 C.E., the empire faced serious difficulties as conflicts between the different ethnic groups staying at Tula led to civil strife. By the mid-twelfth century, large amounts of migrants, mostly nomadic peoples from northwestern Mexico, had entered Tula and settled in the nearby area. By 1175 C.E., the combination of civil opposition and nomadic raid had devastated the Toltec...