began in A.D. 306, were devoted to the establishment of his power in Britain, where the flower of the Western army was concentrated,—­foreseeing a desperate contest with the five rivals who shared between them the Empire which Diocletian had divided; which division, though possibly a necessity in those turbulent times, would yet seem to have been an unwise thing, since it led to civil wars and rivalries, and struggles for supremacy.  It is a mistake to divide a great empire, unless mechanism is worn out, and a central power is impossible.  The tendency of modern civilization is to a union of States, when their language and interests and institutions are identical.  Yet Diocletian was wearied and oppressed by the burdens of State, and retired disgusted, dividing the Empire into two parts, the Eastern and Western.  But there were subdivisions in consequence, and civil wars; and had the policy of Diocletian been continued, the Empire might have been subdivided, like Charlemagne’s, until central power would have been destroyed, as in the Middle Ages.  But Constantine aimed at a general union of the East and West once again, partly from the desire of centralization, and partly from ambition.  The military career of Constantine for about seventeen years was directed to the establishment of his power in Britain, to the reunion of the Empire, and the subjugation of his colleagues,—­a long series of disastrous civil wars.  These wars are without poetic interest,—­in this respect unlike the wars between Caesar and Pompey, and that between Octavius and Antony.  The wars of Caesar inaugurated the imperial regime when the Empire was young and in full vigor, and when military discipline was carried to perfection; those of Constantine were in the latter days of the Empire, when it was impossible to reanimate it, and all things were tending rapidly to dissolution,—­an exceedingly gloomy period, when there were neither statesmen nor philosophers nor poets nor men of genius, of historic fame, outside the Church.  Therefore I shall not dwell on these uninteresting wars, brought about by the ambition of six different emperors, all of whom were aiming for undivided sovereignty.  There were in the West Maximian, the old colleague of Diocletian, who had resigned with him, but who had reassumed the purple; his son, Maxentius, elevated by the Roman Senate and the Praetorian Guard,—­a dissolute and imbecile young man, who reigned over Italy; and Constantine, who possessed Gaul and Britain.  In the East were Galerius, who had married the daughter of Diocletian, and who was a general of considerable ability; Licinius, who had the province of Illyricum; and Maximin, who reigned over Syria and Egypt.