Terraces of Machu Picchu

Machu Picchu was believed by, Richard L. Burger, professor of anthropology at Yale University, to have been built in the 1450s. However, a 2021 study led by Burger used radiocarbon dating to reveal that Machu Picchu may have been occupied from around 1420–1530 AD. Construction appears to date from two great Inca rulers, Pachacutec Inca Yupanqui (1438–1471) and Túpac Inca Yupanqui (1472–1493). There is a consensus among archeologists that Pachacutec ordered the construction of the royal estate for his use as a retreat, most likely after a successful military campaign. Although Machu Picchu is considered to be a "royal" estate, it would not have been passed down in the line of succession. Rather it was used for 80 years before being abandoned, seemingly because of the Spanish conquests in other parts of the Inca Empire. It is possible that most of its inhabitants died from smallpox introduced by travelers before the Spanish conquistadors arrived in the area.