Extreme Droughts Aided Rise of Islam in Arabia 1,500 Years Ago

Extensive droughts in sixth-century Arabia may have led to the demise of the ancient Himyarite Kingdom and contributed to the rise of the religion of Islam, according to historical data.

The Himyarite Kingdom was a civilization located approximately in today's Yemen. The Himyarites are thought to have ruled much of southern Arabia from about 115 BC up to the year 525AD, when the kingdom fell to invaders from Christian Ethiopia.

For decades Judaism and Christianity had gained footholds in the region, both of which existed before the religion of Islam which was proclaimed in Arabia by the prophet Muhammad in the 7th century.

Today Islam is one of the most-practiced religions in the world, with roughly a quarter of the entire world's population being Muslim according to a Pew Research Center estimate in 2015. This makes it the second most-practiced religion after Christianity.

A new study has investigated the origins of Islam and the cultural conditions in which it became established by investigating climate conditions at the time.

The team of scientists, led by Dominik Fleitmann, a geologist and palaeoclimatologist at the University of Basel in Switzerland, did this investigating centuries-old climate data stored inside the Al Hoota Cave in present-day Oman.

Specifically, the team analyzed the layers of a stalagmite—a mound of mineral deposits rising up from a cave floor.

These mineral deposits are useful for studying historic climate data because scientists can use them to infer annual rainfall amounts, among other things. This is because the shape and composition of the stalagmites changes over time.

For example, when less water drips through the ground and onto the stalagmite, the smaller the stalagmite's diameter gets.

Crescent moon on mosque and cracked desert
A stock photo shows an Islamic crescent moon symbol on a mosque (L) and another stock photo shows a dry, cracked desert (R). An Arabian drought may have coincided with conditions that gave rise to Islam, a study has suggested. Getty/Studia72/happy8790

One particular stalagmite in the Al Hoota Cave suggested that there had been a dry period lasting several decades. By analyzing the radioactive decay of uranium within the mineral deposit, the researchers dated this drought to the early sixth century CE, albeit with an error margin of about 30 years.

The researchers also looked at other sources including data about the water level of the Dead Sea and historical documents describing a long drought in the region that were dated to 520 CE.

Fleitmann and his colleagues think the drought contributed to the fall of the Himyarite Kingdom at around that time, which allowed for the subsequent rise of Islam in the region.

In a press release, Fleitmann said the research did not suggest that the drought directly lead to the emergence of Islam but was "an important factor" in major societal changes at that time.

"The population was experiencing great hardship as a result of starvation and war," he said. "This meant Islam met with fertile ground: people were searching for new hope, something that could bring people together again as a society. The new religion offered this.

"It was a bit like a murder case: we have a dead kingdom and are looking for the culprit. Step by step, the evidence brought us closer to the answer."

The research was published in the journal Science on June 16th this year.

Droughts are known to have been involved in the fall of many other civilizations.

The Himyarite Kingdom was not the first to fall in the midst of drought conditions. Other studies have found that the Akkadian Empire in Syria suffered a sudden climate shift that brought arid conditions, as implied by a large increase in dust 4,200 years ago that likely coinncided with a 100-year drought. One study said this shift was "a key factor contributing to the collapse of the Akkadian Empire."

The Maya civilization that existed up to 900 AD in Mexico is also thought to have been hit by a drought that killed millions of its people.

Countries across the world are currently facing record-breaking droughts and heatwaves. The U.S. southwest is currently in what scientists call a "megadrough"—a drought that lasts for more than 30 years. One study published in February found the ongoing drought in the region is the most extreme in 1,200 years.

Anthropogenic climate change is also expected to make parts of Africa so hot it will be uninhabitable for humans in the next three decades. A 2021 report from The World Bank predicts up to 86 million people in Africa will migrate within their own countries by 2050 as a result of climate change.

This article has been updated with additional context throughout.