An eminent classical historian (Founders of the Western World, 1991, etc.) skillfully records the turbulent life of the first Christian Roman emperor and founder of Constantinople, Constantine the Great (c. 272--337). Constantine grew up during the Tetrarchy, a system in which the Roman Empire was divided into western and eastern halves, each headed by an emperor (""Augustus"") and a deputy (""Caesar""). Constantine was the son of Constantius I Chlorus, a rough soldier of bumble origin who rose to become the Caesar to Diocletian's co-emperor Maximian in 286. When Constantius was made Caesar of the western half, Constantine was left at the court of Diocletian until the resignation of Diocletian and Maximian in 305, leaving Constantius and Galerius as emperors. When Constantius died at York in 306, his troops hailed Constantine as the new emperor. Although Constantine showed genius as a general, Grant points out that he achieved his greatest victories in battles against fellow Romans: The author narrates Constantine's triumphs in the protracted civil wars with rivals Maximian and his son Maxentius in 310 and 312 and his giant victory over co-emperor Licinius at Hadrianopolis in 334, in which Constantine consolidated his control over the entire empire. Constantine dealt pitilessly with any challenge: Among his many victims, he had his eldest son Crispus murdered (326) based on charges from his (Constantine's) wife Fausta that Crispus was plotting to usurp the throne, and then had Fausta murdered on charges of adultery. Although the founding of Constantinople (330) and the establishment of state Christianity (312) were great achievements, Grant concludes that Constantine ""had a lot to answer for."" Finally, despite the precedent of the Tetrarchy, he divided the empire among his sons at his death, thus ensuring another round of debilitating civil wars. A highly readable and superbly researched biography of a man whose achievements transformed the decaying Roman Empire and had a lasting impact on Europe.