"Best-selling author Graham Robb finds that the 2,000-year-old map of Ptolemy unlocks a central mystery of British history. Two years ago, Graham Robb moved to a place of legend called the Debatable Land, an independent territory that once served as a buffer between Scotland and England. The oldest detectable territorial division in Great Britain, the Debatable Land was once the bloodiest region in the country. After most of its population was slaughtered or deported, it became the last part of Great Britain to be conquered by England and Scotland. Today, it has vanished from the map and its boundaries are matters of myth and generational memories. Under the spell of a powerful curiosity, Robb began a journey--on foot, by bicycle, and into the past. After correcting the grid of Ptolemy's map, Robb located lost towns and roads and discovered the true history of this maligned patch of land. These personal and scholarly adventures reveal an epic tale of Roman, medieval, and present-day Br