The Inca Empire was once the largest civilization of the Western Hemisphere; indeed, some historians consider it to be the largest American civilization ever. Yet, major questions about its history and culture persist, in large part because the Inca did not have a written language and much of their history was passed down orally and later recorded by Spanish colonizers, who often lacked a clear understanding or appreciation of Inca culture. Additionally, the Inca lived high in the Andes Mountains, where some areas were largely inaccessible to earlier archaeologists.

Inca culture was flourishing culturally when it was attacked and dismantled by Spanish colonizers. The civilization that predated the Inca, the Wari Empire, declined between 1000 C.E. and 1100 C.E., in part because of a major climate disruption. Warming temperatures and severe drought likely ruined crops and resulted in the empire’s fall. Then, in the 1100s, the Inca people began to consolidate into a small but organized community, establishing a capital in Cuzco. According to Inca tradition, Manco Cápac, an Inca leader and founder of the dynasty, led his people to their new home.

The reach of the Inca remained relatively small for several hundred years, until the 14th century when Emperor Mayta Cápac began taking over adjacent lands and expanding Inca territory. Even with this new growth, however, the Inca would not become an empire until the early 15th century, when Viracocha Inca, who had already made a name for himself as a fierce warrior, came to power. Under his rule, the Inca began taking land south of their capital and bringing neighboring peoples under their control.

The Inca sometimes took land by force, but other times they expanded into new areas peacefully, using diplomacy to gain trust. One way the Inca sometimes earned the support of other Indigenous people was by sacrificing llamas and other animals to the local gods of newly acquired lands. Researchers say that animal sacrifice was an important Inca tradition often used to curry favor.

At the same time, the Inca used force to maintain their holdings. They set up military posts to establish a permanent presence in the lands they took over. If they sensed that people were planning to resist, the Inca forced them to relocate. Inca leaders broke up groups bound by ethnicity and culture by moving some of their members to areas that had already assimilated into Inca society. They also moved people who were loyal to the empire to areas that recently came under Inca rule. Similarly, European colonizers sent groups of White Europeans to the Americas and harmed Indigenous people’s ways of life. Both groups forced assimilation and destroyed local culture to break up resistance efforts.

When Viracocha Inca’s reign ended and his son Pachacuti’s reign began, the Inca Empire reached the peak of its range and advancement. In addition to reviving a road system created by the Wari hundreds of years earlier, the Inca also built new highways connecting the northern and southern areas of their empire. The intricate system included suspension bridges made from vines and tunnels carved from rocks throughout the roadway, which was primarily used by the military.

The Inca also furthered developments in agricultural sciences. They created a series of terraces in the mountains that were used as fields, which made it possible to grow a wide variety of crops at a high altitude. They also had complex irrigation systems that fed water to these fields, including one that used canals to conserve and clean water. The Inca became so prolific at agriculture that they needed to create storehouses to hold extra food. They kept track of their yields with quipus, a system of knots tied in multicolored strands that represented information about food, people and more. While the Inca had no written language, some historians think that the Inca used the quipu for words and narratives.

Inca kings built their own royal estates, which were large complexes of buildings with different functions. One of the most famous of these royal estates is Machu Picchu, a palace likely built by Emperor Pachacuti Inca Yupanqui that is now a UNESCO World Heritage site. The many buildings at Machu Picchu include temples, agricultural structures, administrative buildings and residential houses. The site also includes courtyards and grottos that were likely used for ceremonies and community activities.

Inca kings remained important to the Inca people even in death. Like the ancient Egyptians, Inca leaders were mummified to help the body pass into the afterlife. But whereas Egyptian mummies were intended to be permanently entombed, Inca mummies were brought out to connect people to the gods during important festivals. Inca mummies were dressed in fancy clothing and were often given goods and food in return for helping people reach their gods.

In the 1490s, Huayna Capac took control of the Inca Empire. While he was fighting to maintain the borders of the Inca Empire, he contracted a disease that likely came from Spanish colonizers in present-day Ecuador. The disease killed him and left the Inca Empire vulnerable to Spanish conquest. The empire fell to two brothers, Atahualpa and Huascar, each of whom controlled about half of the territory and battled for control of the full empire. Atahualpa won the battle, but his victory was short-lived, as Spanish conquistadors led by Francisco Pizarro took Atahualpa prisoner in a surprise attack, eventually killing him. The Spanish then installed a series of rulers under the control of Spain.

The instability of this period and the diseases brought by Europeans weakened local rulers who might otherwise have been able to unify and resist the colonizing takeover, though it would take until 1572 for Spanish conquistadors to take all of the land once controlled by the Inca. The Inca resisted by continuing the care of mummified kings until 1559, when Spanish leaders took all of the mummies they could find, displaying them for a time for Spanish colonists in Lima, the colonial capital.