A “fascinating and engaging” study of the naval commander who defied an emperor and ruled in Britain and northern Gaul for a decade (Midwest Book Review). In the middle of the third century AD, Roman Britain’s regional fleet, the Classis Britannica, disappeared. It was never to return. Soon the North Sea and English Channel were overrun by Germanic pirates preying upon the east and south coasts of Britain, and the continental coast up to the Rhine Delta. The western augustus (senior emperor) Maximian turned to a seasoned naval leader called Marcus Aurelius Mausaeus Valerius Carausius to restore order. He was so successful that Maximian accused him of pocketing the plunder he’d recaptured—and ordered his execution. The canny Carausius moved first, and in 286 usurped imperial authority, creating a North Sea empire in northern Gaul and Britain that lasted until 296. Dubbed the pirate king, he initially thrived, seeing off early attempts by Maximian to defeat him. However, in the early 290s Maximian appointed his new caesar (junior emperor), Constantius Chlorus—the father of Constantine the Great—to defeat Carausius. A seasoned commander, Constantius Chlorus soon brought northern Gaul back into the imperial fold, leaving Carausius controlling only Britain. But that control would soon come to an end in dramatic fashion, as recounted in this lively, compelling history.