In the autumn of 2011, while a civil war ripped across Libya and the long reign of dictator Muammar Gaddafi came apart in gunfire, a team of archaeologists in England announced that they had located more than 100 lost towns and villages in the middle of the Sahara. Making it all the more amazing, they had spotted the ancient settlements from space.

Working from high-resolution satellite images, some of them originally shot for the oil industry, along with aerial photographs taken decades earlier, researchers at the University of Leicester traced the outlines of fortified farms, castle-like compounds with mudbrick walls still standing over 10 feet high, cemeteries, wells, and the faint geometrical patterns of vanished field systems. The remains ran for several miles through land that now receives almost no rain at all. David Mattingly, the project's leader and a professor of Roman archaeology, compared the discovery to arriving in England and stumbling on all of its medieval castles at once, unremarked and unrecorded. The difference was that these compounds sat in one of the harshest environments on the surface of the planet, hundreds of miles south of the Mediterranean coast and beyond the last easily accessible oasis, in a landscape that offers travelers no water, no shade, and no mercy.

The civilization who built the settlements were the Garamantes, a group that few people outside of historians are familiar with, and their obscurity is part of the story. For most of recorded history, the Garamantes existed only as a rumor on the margins of other people's books, included in a handful of strange paragraphs written by Herodotus and Pliny the Elder, as well as one line about desert raiders written by Tacitus. One Roman monument in North Africa boasts about dealing with them, and the Romans who met them wrote them off as uncouth barbarians who prowled the southern rim of the Roman Empire and made trouble for the coastal cities.