with permanent militia improving agriculture through irrigation and new styles of ceramic art. At the Altiplano, Tiahuanaco or Tiwanaku (100 BC – 1200 AD, Bolivia) managed a large commercial network based on religion. Around the 7th century, both Tiahuanaco and Wari or Huari Empire (600–1200, Central and northern Peru) expanded its influence to all the Andean region, imposing the Huari urbanism and Tiahuanaco religious iconography. The Muisca were the main indigenous civilization in what is now Colombia. They established the Muisca Confederation of many clans, or cacicazgos, that had a free trade network among themselves. They were goldsmiths and farmers. Other important Pre-Columbian cultures include: the Cañaris (in south central Ecuador), Chimú Empire (1300–1470, Peruvian northern coast), Chachapoyas, and the Aymaran kingdoms (1000–1450, Western Bolivia and southern Peru). Holding their capital at the great city of Cusco, the Inca civilization dominated the Andes region from 1438 to 1533. Known as Tawantin suyu, and "the land of the four regions," in Quechua, the Inca Empire was highly distinct and developed. Inca rule extended to nearly a hundred linguistic or ethnic communities, some nine to fourteen million people connected by a 25,000 kilometer road system. Cities were built with precise, unmatched stonework, constructed over many levels of mountain terrain. Terrace farming was a useful form of agriculture. The Mapuche in Central and Southern Chile resisted the European and Chilean settlers, waging the Arauco War for more than 300 years. European colonization In 1494, Portugal and Spain, the two great maritime European powers of that time, on the expectation of new lands being discovered in the west, signed the Treaty of Tordesillas, by which they agreed, with the support of the Pope, that all the land outside Europe should be an exclusive duopoly between the two countries. The treaty established an imaginary line along a north–south meridian 370 leagues west of the Cape Verde Islands, roughly 46° 37' W. In terms of the treaty, all land to the west of the line (known to comprise most of the South American soil) would belong to Spain, and all land to the east, to Portugal. As accurate measurements of longitude were impossible at that time, the line was not strictly enforced, resulting in a Portuguese expansion of Brazil across the meridian. Beginning in the 1530s, the people and natural resources of South America were repeatedly exploited by foreign conquistadors, first from Spain and later from