(CN) — Extreme environmental conditions may have contributed to the decline of a major power in sixth century Arabia, researchers find, in a paper published Thursday in the journal Science.
With a combination of hydrological, historical and archeological records, the study describes a possible link between a period of extreme drought and the fall of the Himyarite kingdom in early sixth century Arabia, and the subsequent rise of Islam in the area. Historians have long debated the political and economic conditions that could have led to the decline of this once powerful society, and while explanations for the fall of the Himyarite kingdom have been the source of frequent study, this collaboration between geology and history provided a new backdrop for what researchers already know.
Using samples from stalagmites found in Hoti Cave in northern Oman, Dominik Fleitmann, a professor of environmental sciences at the University of Basel in Switzerland and an author of the study, found that there was a significant fluctuation in the formation of these stalagmites around 520 to 532 CE.
“Stalagmites are like climate dropping into a cave. There is the rainfall above the cave and the rainfall infiltrates into the bedrock and forms the stalagmite, so the stalagmites are like petrified rainwater,” Fleitmann explains. “Rainfall has an isotopic composition that is like a fingerprint. The fingerprint depends on the climate and condition, the temperature, the amount of rainfall.”
These oxygen and carbon isotopes reflected a reduction in precipitation during those years. By studying these isotope records, Fleitmann and his team were able to determine that this decade of significant aridity coincided with both external and internal clashes that weakened the Himyarite kingdom. Other sources, including historical data on water levels of the Dead Sea, further confirm a particularly severe and lengthy regional drought.
Spanning across the southern Arabian Peninsula in the area now known as Yemen, the Himyarite kingdom was formally established in the third century, and flourished for the next hundred or so years, with a centralized governing system and robust foreign trade. Although they had enjoyed relative wealth and stability, the kingdom, feeling the effects of the drought by the mid-sixth century, was plagued by declining trade, internal conflict between elite clans and interventions from outside forces, including the Byzantine and Sasanian Empires. A primarily Jewish population, Himyar was also besieged by the Christian kingdom of Aksum, their neighbors from present day Ethiopia, who would eventually conquer the kingdom in the 520s.
Water was an especially important resource for the Himyarite kingdom. The study notes, “The importance of agriculture is evidenced by widespread terraced fields in the highlands, numerous irrigation systems along the desert margin, and a considerable expansion of hydraulic structures between the first and fourth centuries CE.”
The drought began to affect agricultural yield, which opened the kingdom up to further destabilization.
John Haldon, professor emeritus of European and Byzantine History and Hellenic studies at Princeton University and another author of the study, clarifies, “We’re supposing this drought would have weakened the economic, and therefore the political, infrastructure of Himyar. And that made it susceptible to the foreign pressure. This drought really helps us to see a context in which Himyar would have collapsed much more readily than the one that we had.”
Haldon also stressed the importance of the kingdom’s central power and the way its eventual break down opened them up to political downfall.
The power vacuum left by the fall of the Himyarite kingdom produced major political and socioeconomic changes in the Arabian Peninsula, as well as cultural and religious transformations. The changes, the study suggests, may have primed the area for the eventual establishment of Islam in the early seventh century.
The study is careful to establish that although there is a correlation between the extreme weather and the unstable conditions of the kingdom, the drought had an influence but did not directly cause the fall of the Himyarite kingdom, nor was it a cause for the eventual rise of Islam in the area. It suggests that environmental factors should be considered as a factor, when considering history as whole, to contextualize the wider geopolitical sphere.