Inca – Andean Region - 1200 to 1532 CE
The Inca, who built the spectacular city of Machu Picchu high in the Andes, were the last in a long line of cultures of the Ancient Americas prior to Spanish conquest. At the height of its power, which lasted for little more than a century, the Inca Empire extended throughout the Andes, from present-day Colombia down to Chile -- a stretch of more than 5635km (3,500 miles). At its apex, the Inca Empire's domain was larger than the Roman Empire. The Incas' dominance was achieved through formidable organization and a highly developed economic system. The Incas rapidly expanded their empire first through political alliances and absorption, and then by swift military conquest. The Incas succeeded in achieving political and religious unification across their vast network.