The effective conquest by Rome started in 43 AD ... was divided into numerous tribal sub-kingdoms made part of the Roman Empire through conquest or treaty. Latin was the official language ...

"A sequence of severe summer droughts from 364 to 366 not only contributed to prolonged harvest failures and food shortages, ...

"These factors limited resilience, and meant a drought-induced, partial-military rebellion and subsequent external invasion were able to overwhelm the weakened defenses." The researchers expanded ...

partial-military rebellion and subsequent external invasion were able to overwhelm the weakened defences." The researchers expanded their climate-conflict analysis to the entire Roman Empire for ...