Quirks & Quarks

How volcanoes helped the Romans destroy Egyptian rule

The Ptolomaic dynasty was undermined by volcanoes that short-circuited life-giving Nile floods

Cleopatra's dynasty brought down by volcanoes

Relief portraits of Cleopatra and her son Ceasarion, on the Dendera Temple. (Wikimedia Commons)

A great dynasty undermined

The Ptolemaic dynasty ruled Egypt from 305 BCE until the death of Queen Cleopatra and the Roman conquest in 30 BCE. In some ways this was a golden age, as Egypt was one of the world's most powerful countries, and the great captial of Alexandria was a centre of trade and intellectual life. But the Ptolomaic kings and queens were also plagued by revolt and political unrest throughout their dynasty, and historians have had difficulty explaining just why.

Eruptions lead to revolutions

Dr. Francis Ludlow, a climate historian at Trinity College Dublin, had been studying ice cores which preserved a record of major, climate disrupting, volcanic eruptions. These eruptions can lead to short-term global cooling, but also disrupt weather patterns, including the monsoon that feeds the watershed of the great Nile river. 

In discussions with colleageus, including Egyptian historians, they realized there was a close correlation between these eruptions and political unrest and revolt in Egypt.  

The connection, they think, was in the way eruptions led to the failure of the annual Nile flood, which was vital to agriculture in the Nile valley. So volcanoes led to food shortages, which they think contributed to political unrest and revolt against the rulers of Egypt.

Lessons for today

The Ptolemaic period was a time of relatively frequent large volcanic eruptions, compared to the later time of Roman rule in Egypt, and compared to the last two hundred years as well. 

Dr. Ludlow suspects that this has led to a certain complacency for us today about how disruptive to global weather and agriculture large volcanic eruptions could be in the future.