Older than we knew | Results
Yale archaeologist Richard Burger ’72 had in his possession bone and tooth fragments from 26 bodies that were once buried under the verdant terraces and granite temples of Machu Picchu. He wanted to know the age of these samples. They traveled to a facility at the University of California at Irvine to undergo an advanced form of radiocarbon dating known as accelerator mass spectrometry. The results are back: it turns out that Machu Picchu is a few decades older than previously believed.
“The timeline of the Inca royal family has been a subject of debate for as long as people have studied the subject,” said Burger. “And that’s understandable.” Reconstructions of Inca history have generally relied on a series of deeply flawed accounts written by Spanish invaders between 1530 and 1620, few of which agree with each other.
And yet, out of these discordant accounts emerged an (apparently) authoritative Inca story, published in 1945 by Berkeley archaeologist John Rowe — Burger’s doctoral adviser, in this case. His work was mainly inspired by a single Spanish account written by Cabello de Balboa in 1586 and, according to Rowe, the construction of Machu Picchu dates from 1450 or 1460. It was a decade or two after 1438, when the emperor Pachacuti is reported to have conquered the lower Urubamba valley.
But Burger’s radiocarbon dates push back the founding of Machu Picchu to around 1420. This suggests that Pachacuti’s rise to power and the Inca’s emergence as the largest and most powerful empire in pre-Columbian America have happened earlier than previously thought. Burger and his team published their findings in the journal antiquity.
Burger also disagrees with those who claim that Machu Picchu was founded long before 1420. They are “struck by the fact that the Inca footprint is so powerful and so deep,” he says. and Bolivia – and they argue that the Incas could not have come to power so quickly. But “nothing indicates that Machu Picchu was built before the 15th century,” he adds. “This work suggests that those who consider the possibility that the Inca Empire lasted more than a century are not correct.”
Burger’s work continues a long-standing connection between Yale and Machu Picchu, which began when Hiram Bingham III ’98, assistant professor of Latin American history, first revealed the site to the global scientific community in 1911. For his radiocarbon dating, Burger used samples originally unearthed by Bingham. But his work also marks a break with that of his predecessors.
“With the Incas – and they are not the only example – we have long favored documents in the telling of history, with archaeological evidence sometimes being relegated to illustrating what we have learned from documents,” says Burger. “This work shows how limited documents can be. Hard evidence often contains more truth than people’s memories.