Xochicalco is an archaeological site in the modern state of Morelos, in central Mexico. The ancient city rose to power around 650 ce and was an important political and religious center until 900 ce. At the time of the Spanish Conquest, Xochicalco was part of the Aztec tribute province of Cuauhnahuac and was recognized as an important place in native historic traditions.
Xochicalco developed during a period of cultural upheaval and rapid sociopolitical change in central Mexico. The period between 650 and 900 was characterized by the decline of the powerful center of Teotihuacán, the breakup of its pan-Mesoamerican empire, an increase in militarism, and the emergence of independent, competing city-states within Teotihuacán's former political domain. Xochicalco is representative of all these features. During its maximum development the site covered an area of approximately 1.5 square miles and supported a population of between 10,000 and 15,000 people. Xochicalco is the earliest known fortified city in central Mexico. The site was constructed over a series of low hills, and seven defensive precincts have been identified that were fortified using ramparts, dry moats, and concentric terracing.
Most of western Morelos was under Xochicalco's direct political control between 650 and 900. Political power is evident in the scale of monumental architecture, including the construction of central Mexico's first and only paved road system, which linked Xochicalco with outlying sites in the region. Xochicalco engaged in long-distance trade with many areas of Mesoamerica, including the Gulf Coast, Oaxaca, and the Maya region. The site's many sculpted monuments identify the three earliest named rulers in central Mexico, and the Pyramid of the Plumed Serpents was venerated as a sacred place at the time of the Conquest.
Xochicalco society represents an early expression of the Aztec cultural pattern. This pattern is characterized by military conquest, the formation of tribute empires, internal social stratification based on participation in warfare, and the practice of human sacrifice, which was linked to the religious practice of nourishing the gods through sacrificial ritual.
Hirth, Kenneth. "Xochicalco: Urban Growth and State Formation in Central Mexico." Science 225 (1984): 579-586.
Hirth, Kenneth. "Militarism and Social Organization at Xochicalco, Morelos." In Mesoamerica after the Decline of Teotihuacán, A.D. 700–900, ed. Richard A. Diehl and Janet Catherine Berlo. Washington, DC: Dumbarton Oaks Research Library and Collection, 1989.
Hirth, Kenneth. Ancient Urbanism at Xochicalco. Salt Lake City: University of Utah Press, 2000.
Litvak King, Jaime. "Xochicalco en la caída del Clásico, una hipótesis." Anales de Antropología 8 (1970): 102-124.
Piña Chán, Román. Xochicalco: El mítico Tamoanchán. Mexico City: Instituto Nacional de Antropología e Historia, 1989.