The drought defeated the Roman Britain before the wild bars

Ancient Tree Ring revealed that a third year in a row had weakened Rome’s Britain before the devastating “Wild Conspiracy” of 367 CE.

Cambridge University-led research; Climate changecombining the historical Roman records with the Treeling record, shows how the climate extremes caused a cascade of social disruption that ultimately contributed to Rome’s withdrawal from Britain.

“There is not much archaeological evidence for the ‘Barbarian conspiracy’. The written explanation of the period provides background, but our findings explain the catalysts for this major event.”

By analyzing the rings of ancient oak trees, researchers reconstructed precipitation in the southern UK at a critical time. They found that during the important growth period from April to July, the 364-366 years experienced rainfall at just 54-72% of normal levels.

“Three consecutive droughts would have had a devastating effect on the productivity of Rome Britain’s most important agricultural regions. As Roman writers tell us, this led to all the food shortages of the unstable social effects it has.”

This timing proved disastrous for the British in Rome. The state’s agricultural practices relied on spring-sinking crops, particularly vulnerable to early summer droughts. Grain supply to the military risons has declined as the harvest failed for the third year in a row. Ammianus Marcellinus of the Roman Chronicle described the British population as “the greatest condition of hunger” by 367 AD.

This environmental crisis created the perfect conditions for subsequent coordinated attacks. Elements of the Roman garrison on Hadrian’s wall likely suffered from food shortages, rebelling and allowing northern tribes to pour into the provinces. The state’s military leaders were reportedly killed or captured, while some soldiers were reportedly abandoned to join the invaders.

The study also expanded beyond the UK to analyze climate patterns before 106 fights across the Roman Empire between 350 and 476 AD. They discovered a statistically significant pattern of battles that occur after a period of drought in the Western Empire.

“The relationship between climate and conflict is becoming more and more apparent in our own time, so these discoveries are not important to historians,” says Cambridge co-author Tatiana Bevchuk. “Extreme climatic conditions lead to hunger, which can lead to social challenges, and ultimately lead to complete conflict.”

Rome eventually restored order in Britain, but the provinces never fully recovered. The last official Roman regime left Britain around 410 AD, just 43 years after the wildlife conspiracy.

The findings show how even powerful empires can be vulnerable to environmental shocks cascaded through agricultural systems and social structures, and ultimately can cause conflict and political transformation.