Science and the Assyrians: how science uncovers the 2600-year-old drought of the Assyrian Empire. From the article:

The Neo-Assyrian Empire, centered in northern Iraq and extending from Iran to Egypt — the largest empire of its time — collapsed after more than two centuries of dominance at the fall of its capital, Nineveh, in 612 B.C.E…

Numerous theories about the collapse have been put forward since the city and its destruction levels were first excavated by archaeologists 180 years ago. But the mystery of how two small armies — the Babylonians in the south and the Medes in the east — were able to converge on Nineveh and completely destroy what was then the largest city in the world, without any reoccupation, has remained unsolved.

A team of researchers — using archival and archaeological data contributed by Harvey Weiss, professor of Near Eastern archaeology and environmental studies at Yale — was able for the first time to determine the underlying cause for the collapse. By examining new precipitation records of the area, the team discovered an abrupt 60-year megadrought that so weakened the Assyrian state that Nineveh was overrun in three months and abandoned forever. The research was published in Science Advances on Nov. 13….

The team analyzed stalagmites — a type of speleothem that grows up from a cave floor and is formed by the deposit of minerals from water — retrieved from Kuna Ba cave in northeast Iraq. The speleothems can provide a history of climate through the oxygen and uranium isotope ratios of infiltrating water that are preserved in its layers. Oxygen in rainwater comes in two main varieties: heavy and light. The ratio of heavy to light types of oxygen isotopes are extremely sensitive to variations in precipitation and temperature. Over time, uranium trapped in speleothems turns into thorium, allowing scientists to date the speleothem deposits.

Weiss and the research team synchronized these findings with archaeological and cuneiform records and were able to document the first paleoclimate data for the megadrought that affected the Assyrian heartland at the time of the empire’s collapse, when its less drought-affected neighbors invaded. The team’s research also revealed that this megadrought followed a high-rainfall period that facilitated the Assyrian empire’s earlier growth and expansion.

For other posts on the use of science in history, see here.