Constantine is the man of the hour. The 1700th anniversary of his ascent into the ruling circle of the Roman Empire, just as the administration of shared authority instituted by Diocletian was about to break apart in civil war, is being celebrated across Europe. Rimini led off in 2005 with an important show and sumptuous catalogue (Angela Donati and Giovanni Gentili, eds., Costantino il Grande: La civiltà antica al bivio tra Occidente e Oriente, Milano: Cinisello Balsamo, 2005). The volume under review here, the catalogue of York’s effort in the fall of 2006, is the second entry in the Constantinian sweepstakes. And coming in the summer and fall of 2007, Trier will launch a triple venue exhibition, Konstantin der Grosse, at the Rheinisches Landesmuseum, the Bischöfliches Dom- und Diözesanmuseum, and the Stadtmuseum Simeonstift. The young Constantine was providentially in York when his father, Constantius Chlorus, died there in July of 306. Under the rules of Diocletian’s system, as renewed in its second phase when Diocletian and his colleague Maximian retired in 305, the succession to Constantius Chlorus as senior partner of the western duo belonged to his junior colleague Flavius Valerius Severus. But the soldiers in York saluted Constantine as...