By the death of Crispus, the inheritance of the empire seemed to devolve on the three sons of Fausta, who have been already mentioned under the names of Constantine, of Constantius, and of Constans. These young princes were successively invested with the title of Cæsar; and the dates of their promotion may be referred to the tenth, the twentieth, and the thirtieth years of the reign of their father. This conduct, though it tended to multiply the future masters of the Roman world, might be excused by the partiality of paternal affection; but it is not easy to understand the motives of the emperor when he endangered the safety both of his family and of his people, by the unnecessary elevation of his two nephews, Dalmatius and Hannibalianus. The former was raised, by the title of Cæsar, to an equality with his cousins. In favour of the latter, Constantine invented the new and singular appellation of “nobilissimus”; to which he annexed the flattering distinction of a robe of purple and gold. But of the whole series of Roman princes in any age of the empire, Hannibalianus alone was distinguished by the title of king, a name which the subjects of Tiberius would have detested as the profane and cruel insult of capricious tyranny. The use of such a title, even as it appears under the reign of Constantine, is a strange and unconnected fact, which can scarcely be admitted on the joint authority of imperial medals and contemporary writers.
The whole empire was deeply interested in the education of these five youths, the acknowledged successors of Constantine. The exercises of the body prepared them for the fatigues of war and the duties of active life. Those who occasionally mention the education or talents of Constantius allow that he excelled in the gymnastic arts of leaping and running; that he was a dexterous archer, a skilful horseman, and a master of all the different weapons used in the service either of the cavalry or of the infantry. The same assiduous cultivation was bestowed, though not perhaps with equal success, to improve the minds of the other sons and the nephews of Constantine. The most celebrated professors of the Christian faith, of the Grecian philosophy, and of the Roman jurisprudence were invited by the liberality of the emperor, who reserved for himself the important task of instructing the royal youths in the science of government and the knowledge of mankind. But the genius of Constantine himself had been formed by adversity and experience. In the free intercourse of private life and amidst the dangers of the court of Galerius, he had learned to command his own passions, to encounter those of his equals, and to depend for his present safety and future greatness on the prudence and firmness of his conduct. His destined successors had the misfortune of being born and educated in the imperial purple. Incessantly surrounded by a train of flatterers, they passed their youth in the enjoyment of luxury and the expectation of a throne; nor would the dignity of their rank permit them to descend from that elevated station from whence the various characters of human nature appear to wear a smooth and uniform aspect.
The indulgence of Constantine admitted them, at a very tender age, to share the administration of the empire; and they studied the art of reigning at the expense of the people intrusted to their care. The younger Constantine was appointed to hold his court in Gaul; and his brother Constantius exchanged that department, the ancient patrimony of their father, for the more opulent, but less martial, countries of the east. Italy, the western Illyricum, and Africa were accustomed to revere Constans, the third of his sons, as the representative of the great Constantine. He fixed Dalmatius on the Gothic frontier, to which he annexed the government of Thrace, Macedonia, and Greece. The city of Cæsarea was chosen for the residence of Hannibalianus; and the provinces of Pontus, Cappadocia, and the lesser Armenia were destined to form the extent of his new kingdom. For each of these princes a suitable establishment was provided. A just proportion of guards, of legions, and of auxiliaries was allotted for their respective dignity and defence. The ministers and generals who were placed about their persons were such as Constantine could trust to assist, and even to control, these youthful sovereigns in the exercise of their delegated power. As they advanced in years and experience the limits of their authority were insensibly enlarged: but the emperor always reserved for himself the title of Augustus; and while he showed the cæsars to the armies and provinces, he maintained every part of the empire in equal obedience to its supreme head. The tranquillity of the last fourteen years of his reign was scarcely interrupted by the contemptible insurrection of a camel-driver in the island of Cyprus, or by the active part which the policy of Constantine engaged him to assume in the wars of the Goths and Sarmatians.