To complete the story, their fall had two factors. They had run-ins with the Romans who captured many of their settlements, and the ground water level fell. >

To complete the story, their fall had two factors. They had run-ins with the Romans who captured many of their settlements, and the ground water level fell. > Roman depictions describe the Garamantes as bearing ritual scars and tattoos. Tacitus wrote that they assisted the rebel Tacfarinas and raided Roman coastal settlements. According to Pliny the Elder, Romans eventually grew tired of Garamantian raiding and Lucius Cornelius Balbus captured fifteen of their settlements in 19 BC. In 202 AD, Septimius Severus captured the capital city of Garama. > The decline of the Garamantian culture may have been connected to worsening climatic conditions, or overuse of water resources. What is desert today was once fairly good agricultural land and was enhanced through the Garamantian irrigation system 1,500 years ago. As fossil water is a non-renewable resource, over the six centuries of the Garamantian kingdom, the ground water level fell. https://en.wikipedia.org/wiki/Garamantes https://en.wikipedia.org/wiki/Garamantes