Andes: pre-Inca civilizations ual decline, until the capital city itself was abandoned by around 1000 The empire’s economic foundations were agropastoral, combining intensive and extensive agriculture with highland pastoralism The dominant feature of the capital city, a structure called the Akapana, consisted of an enormous stone platform measuring some 200 meters on a side and rising some 15 meters high Evidently the ritual and ceremonial center of the city and empire, the flat summit of the Akapana held a sunken court with elaborate terraces and retaining walls in a style reminiscent of Chiripa and other Titicaca sites A nearby structure, called Kalasasaya, prominently displayed the famous Gateway of the Sun, chiseled from a single block of stone and featuring the so-called Gateway God, which some scholars interpret as a solar deity A host of other buildings, walls, compounds, enclosures, and platforms graced the sprawling urban center, which housed an estimated 20,000 to 30,000 inhabitants Like other Andean cities, Tiwanaku had no markets, its goods and services exchanged through complex webs of kinship networks and state-administered redistribution Covering a much larger territory than Tiwanaku was the Huari Empire, with its capital city Huari on the summit of Cerro Baul some 25 kilometers north of the present-day city of Ayacucho in the Central Highlands The Huari state emerged toward the beginning of the Middle Horizon (c 600 c.e.) At its height, around 750 c.e., the empire spanned more than 900 miles along the highlands and adjacent coastal plains, touching the northernmost fringe of the Tiwanaku Empire to the south and extending to the Sechura Desert in the north The capital city, densely packed with walls and enclosures, covered around four square kilometers and is estimated to have housed some 20,000 to 30,000 people The Huari elite ruled their vast empire through a series of administrative colonies or nodes that exercised political domination in the zones under Huari control The Huari Empire is perhaps best known for its extensive agricultural terracing and irrigation projects that spanned large parts of the highlands Requiring enormous expenditures of labor, the Huari terraces, canals, and related reclamation projects transformed millions of hectares of steep arid hillsides into land suitable for cultivation Scholars hypothesize that the extensive terracing and irrigation works undertaken by the Huari state help to explain the empire’s survival through the periodic El Niño–induced droughts and floods that comprise a 11 persistent feature of the highland and coastal environments, and that proved catastrophic for the Moche polity during the same period In order to acquire the vast amounts of labor necessary for the construction of such terraces, irrigation works, and other infrastructure, both the Huari and Tiwanaku Empires compelled subject communities to contribute substantial quantities of labor to the state —a kind of labor tax required of all subject peoples Indeed, Andean polities were predicated on stark social inequalities and the division of society into two broad classes: elites and commoners Public works such as terraces, canals, roads, and urban monumental architecture were built by commoners from ayllus and communities compelled to devote specified quantities of time annually to such endeavors The state and its agents reciprocated by ensuring military security, food security, and other benefits, a reciprocity rooted, at bottom, in a fundamentally unequal relationship between the sociopolitically dominant and dominated With the demise of both the Tiwanaku and the Huari Empires by the end of the Middle Horizon, the Andes entered a period of political decentralization and reassertion of local and regional autonomies An important exception unfolded along the North Coast and its adjacent highland, where the powerful Chimor Empire emerged around 900 c.e With its capital at Chan Chan near the mouth of the Moche River, at its height in the Late Intermediate Period the Chimor Empire spanned nearly 1,000 kilometers from the Gulf of Guayaquil in contemporary Ecuador to the Chillon River valley on the Central Coast Like the Inca Empire that supplanted them in the mid-1400s, Chimor’s rulers deployed a combination of conquest and alliance-building to bring large areas of both coast and highland under their dominion The capital city of Chan Chan was a huge urban complex, housing upwards of 35,000 people and covering at least 20 square kilometers, while its civic core encompassed at least six square kilometers and housed some 6,000 rulers and nobility During the Late Horizon, the young and powerful Inca Empire swept down from its highland capital at Cuzco to bring Chimor, and the rest of highland and coastal Peru, under its dominion (see Volume III) Further reading: Silverman, H., ed Andean Archaeology Malden, MA: Blackwell, 2004; Michael E Moseley, The Incas and Their Ancestors Rev ed London: Thames & Hudson, 2001; Kolata, A L., ed Tiwanaku and Its Hinterland: