Based in central Anatolia, a semi-arid region of present-day Turkey, the Hittites were one of the most influential ancient civilizations in the eastern Mediterranean and the Near East, between 1650 and 1200 BC.

The Hittite Empire and its capital Hattusa, an archaeological site listed as a UNESCO World Heritage Site, established their hegemony over all of Anatolia and the northern Levant (Syria), forged many links with other empires and even competed with the powerful Egyptian empire of Ramses II.

Before collapsing, around 1200: the city of Hattusa, political and religious center, was abandoned then burned, the administration and the writing system disappeared, the royal line died out... All of this, “Pretty quickly”, explains to AFP Sturt Manning, professor of archeology at American University of Cornell, main author of the study published this week in Nature.

Many other Mediterranean civilizations -- such as that of the Mycenaeans -- met the same fate during this same period of the Late Bronze Age.

Several factors are associated with this widespread collapse: attacks by mysterious "Sea Peoples", famines, epidemics, with the backdrop of a shift to a drier and cooler climate over a long period of 300 years.

A dam built by the Hittites in Alacahoyuk, Turkey, in December 2006 © STR / AFP/Archives

But “the trigger” remained an enigma, underlines Müge Durusu-Tanriöver, researcher in art history at the University of Philadelphia, in a comment attached to the study.

Dry junipers

For the Hittites, the answer lay in trees, specifically ancient juniper logs.

They came from the burial mound of Gordion (central Turkey), where a king's tomb was discovered in the 1950s containing one of the oldest wooden structures in the world, very well preserved.

The analysis of the growth rings of this wood - the concentric rings that take shape over time in the heart of the tree - has made it possible to reconstruct with precision the former climatic conditions, according to a discipline called dendrochronology.

Junipers in Lebanon, January 11, 2023 © Ibrahim AMRO / AFP/Archives

"The main obstacle to the growth of trees in central Anatolia, a semi-arid region, is the absence of water", stresses Sturt Manning.

His team therefore went to look for the growth markers recorded in the rings of the junipers.

The researchers identified three consecutive years of abnormally poor growth, suggesting a prolonged and particularly severe drought period between 1198 and 1196 BCE.

A hypothesis confirmed by carbon 12 and 13 dating.

This extreme aridity would have led to long periods of food shortages, since the landlocked territories of the central Hittite kingdom depended on regional grain production and livestock, which were particularly vulnerable to drought.

However, the population had been used to the absence of precipitation for centuries.

But it "could not cope with such brutal climate change. All its strategies for adaptation and resilience to difficult times, such as the storage of grain attested by huge silos, were overwhelmed", comments the Pr Manning.

Food shortages are said to have led to political, economic and social unrest, as well as epidemics, ultimately precipitating the collapse of the empire.

"This study finally gives us a tangible explanation for the abandonment of the city of Hattusa", welcomes Müge Durusu-Tanriöver, hoping that future research will be able to determine if other regions were hit by this period of aridity.

This "point of no return" reached by the Hittite empire underlines, according to her, the vulnerability of our socio-economic systems in the face of the current climate crisis, in particular the viability of large urban centers.

© 2023 AFP