North Africa was one of the richest parts of the Roman Empire, the agricultural powerhouse of the Mediterranean. It was also home to some of the emperor’s biggest imperial estates, and prosperous cities of all kinds. Its loss to the Vandals in the first half of the 5th century AD was the mortal blow which precipitated the fall of the western empire, and set the eastern empire back for decades. Its reconquest then became an obsession with each new emperor in Constantinople. Time and again the eastern Romans failed in this goal, until Justinian I finally succeeded in the AD 530s. Although...