3,200-year-old trees reveal the collapse of an ancient empire

A new study of 3,200-year-old trees in Turkey suggests that the mysterious collapse of several civilisations in the Late Bronze Age, from around 1200 to 1150 B.C., coincided with a severe three-year drought in central Anatolia, a heartland of the powerful Hittite Empire and one of the worst-affected areas at the time.

In what is commonly known as the “Late Bronze Age collapse,” the Hittite Empire and the civilisation of the Mycenaean Greeks, as well as many smaller powers and the trade networks that linked them, fell apart. It also led to anarchy, uprisings, civil wars, and rival pharaohs in Egypt, while Assyria and Babylonia suffered famines, outbreaks of disease, and foreign invasions.

Scholars have struggled for 200 years to explain the collapse as a consequence of volcanic eruptions or earthquakes; piracy, migrations, or invasions; political or economic failures; diseases, famines, or climate change; or even of the spread of iron metallurgy throughout a region dominated by bronze.

Now, research published in Nature reveals that climate change may have played a bigger role in the Late Bronze Age collapse than previously thought.

By examining the logs from trees buried for almost 3,000 years, an American research team has revealed that the heartlands of the Hittite Empire in central Anatolia suffered a severe drought in 1198, 1197, and 1196 B.C.—right at the start of the Late Bronze Age collapse.

The finding strengthens theories that the shift to a drier and colder climate in the eastern Mediterranean upended food production, leading to shortages that exacerbated the cultural and economic problems already roiling the region.

An empire 'disappears'

The Hittite Empire ruled much of Anatolia and what is now Syria from about 1650 until about 1200 B.C. Most famously, they fought Egypt for control of Canaan in 1274 B.C. at the Battle of Kadesh, now near the Syrian city of Homs.

But the Hittites never again ventured so far south, and the new research suggests one of the reasons why: It appears their empire quickly collapsed after the prolonged drought in central Anatolia from 1198 to 1196 B.C, which must have disrupted the essential supply of grain from Hittite farms.

That would have led to widespread food shortages, says Sturt Manning, the study’s lead author and a professor of archaeology at Cornell University; and those food shortages could have combined with factors like wars, social upheavals or outbreaks of disease to bring the Hittite empire to its end soon after 1200 B.C.

“We can’t positively connect these things, because we have no eyewitness accounts,” Manning says. “But it seems an extraordinary coincidence that somewhere around the 1190s to the 1180s the whole empire disappears from history forever.”

Tales of ancient trees

To unravel what happened to the Hittite Empire, Manning’s team looked the kingdom of Phrygia, which arose in the same area centuries later. Some studies suggest the Phrygians were invaders from what are now the Balkans, but many archaeologists think they were descended from the Hittites.

Manning is a renowned expert in the field of dendrochronology, which can determine the exact year when the annual growth rings of trees were formed, and his team examined logs from beneath a giant burial mound near the Phrygian capital Gordion, about 50 miles southwest of Ankara. The mound is associated with the legendary King Midas—he of the “Midas touch”—and the royal tomb beneath it may be the world’s earliest-known wooden building, Manning says.

It was made with over 100 logs from juniper trees felled in the eighth century B.C. which were then preserved beneath the mound. But because junipers can live so long—sometimes more than 1,000 years—the researchers identified 18 logs from trees that were alive when the area was a Hittite heartland.

The team measured the annual growth rings of the trees visible in the logs and examined the levels of the isotope carbon-13 in their cells, which indicates the moisture level of the air when they formed. Both types of evidence were incorporated to create a sort of high-resolution “dryness record” for central Anatolia between around 1500 and 800 B.C.

The end of empires

Before this latest research, studies indicated the region’s climate became drier and cooler over the 300 years after 1200 B.C. But the new dryness record pinpoints a severe drought in 1198, 1197, and 1196 B.C.

Manning stresses that the Hittite Empire probably could have survived a shorter drought, as it had in the past—instead, it was overcome by a drought that lasted for too long. “If you’re running a government in these areas, then you expect occasional droughts and you plan for that,” he says. “But what you don’t expect or plan for is to have year after year of drought.”

Historian and archaeologist Eric Cline at George Washington University wasn’t involved in the latest research. His 2014 book 1177 B.C.: The Year Civilization Collapsed highlights 1177 as a key year when things fell apart, but he says the dates from the new study also make sense.

“The Late Bronze Age collapse and the droughts definitely started before 1177 B.C.,” Cline says. “Having this new evidence for a drought taking place from 1198 to 1196 B.C. fits well within the general scenario of the collapse.”

Archaeologist and historian Lorenzo D’Alfonso of New York University’s Institute for the Study of the Ancient World and Italy’s University of Pavia, who also wasn’t involved in the research, says there is evidence in ice cores from Greenland of an even earlier global drought that hit the Hittites around 1250 B.C.

Ancient writings indicate the Hittite Empire implemented new techniques to store water after that; but they don’t seem to have cut back on their grain production – instead, they increased it, he says. As a result, the Hittite Empire would have been hit harder by this second severe drought about 50 years later.

“When that drought came, they were already over-producing,” D’Alfonso notes.