Marcus was not a success. Soon after his elevation he was pronounced unfit and slain, to make way for Gratian, who reigned for four months (A.D. 407) and then met the fate of Marcus. The third tyrant was a private soldier who bore the auspicious name of Constantine, and was to play a considerable part for a few years on the stage of western Europe.
The first act of Constantine was to cross with an army into Gaul. It has been supposed that he feared an invasion of Britain by the German hordes, who had indeed approached the Channel, and that he went forth to meet the danger. It seems more probable that he was following the example of Magnus Maximus, who had in like manner crossed over to the continent to wrest Gaul and Spain from Gratian. He landed at Boulogne. It appears to be commonly supposed that he took with him all the forces in Britain, not only the field army, but also the garrisons of the frontiers. This is highly improbable. For we cannot imagine that he did not intend to retain his hold on the island, and it has been inferred from the evidence of a coin that he set up a colleague before he sailed.44 But he must have been accompanied by the whole field army, which was not very large, or the greater part of it.
Gaul sorely needed a Roman defender at the head of Roman legions, and the Gallic legions went over to Constantine. He inflicted a severe defeat on the barbarians, we know not where, and he is said to have guarded the Rhine more efficiently than it had been guarded since the reign of Julian — a statement which comes from a pagan admirer of the Apostate. The representatives of Honorius fled to Italy when Constantine passed into the Rhone valley and the south-eastern districts, which had escaped the ravages of the Germans. He seems to have made agreements with some of the intruders,45 which they perfidiously violated. But we know nothing definite as to his dealings with them. “For two years,” writes a modern historian,46 “they and he both carry on operations in Gaul, each, it would seem, without any interruption from the other. And when the scene of action is moved from Gaul to Spain, each party carries on its operations there also with as little of mutual let or hindrance. It was most likely only by winking at the presence of the invaders and at their doings that Constantine obtained possession, so far as Roman troops and Roman administration were concerned, of all Gaul from the Channel to the Alps. Certain it is that at no very long time after his landing, before the end of the year 407, he was possessed of it. But at that moment no Roman prince could be possessed of much authority in central or western Gaul, where Vandals, Suevians, and Alans were ravaging at pleasure. The dominion of Constantine must have consisted of a long and narrow strip of eastern Gaul, from the Channel to the Mediterranean, which could not have differed very widely from the earliest and most extended of the many uses of the word Lotharingia. He held the imperial city on the Mosel, the home of Valentinian and the earlier Constantine.”
When Constantine obtained possession of Arelate (Arles), then the most prosperous city of Gaul, it was time for Honorius and his general to rouse themselves. We saw how Stilicho formed the design of assigning to Alaric the task of subduing the adventurer from Britain, who had conferred upon his two sons, Constans, a monk, and Julian, the titles of caesar and nobilissimus respectively. But this design was not carried out. A Goth indeed, and a brave Goth, but not Alaric, crossed the Alps to recover the usurped provinces; and Sarus defeated the army which was sent by Constantine to oppose him. But he failed to take Valentia, and returned to Italy without having accomplished his purpose (A.D. 408).
The next movement of Constantine was to occupy Spain.47 We need not follow the difficult and obscure operations which were carried on between Spanish kinsmen of Honorius and the troops which the Caesar Constans and his lieutenant Gerontius led across the Pyrenees.48 The defenders of Spain were overcome, and Caesaraugusta (Zaragoza) became the seat of the Roman Caesar. Thus in the realm of Constantine almost all the lands composing the Gallic prefecture were included; he might claim to be the lord of Britain; the province of Tingitana, beyond the straits of Gades, was the only province that had obeyed Honorius and did not in theory obey Constantine.
Constans, however, was soon recalled to Gaul by his father, and elevated to the rank of Augustus. But Constantine himself meanwhile, possessing the power of an Emperor, was not wholly content; he desired also to be acknowledged as a colleague by the son of Theodosius, and become legitimised. He sent an embassy for this purpose to Ravenna (early in A.D. 409), and Honorius, hampered at the time by the presence of Alaric, was too weak to refuse the pacific proposals.49 Thus Flavius Claudius Constantinus was recognised as an Augustus and an Imperial brother by the legitimate emperor; but the fact that the recognition was extorted and soon repudiated, combined with the fact that he was never acknowledged by the other Augustus at New Rome, might justify us in refusing to include the invader from Britain who ruled at Arelate in the numbered list of Imperial Constantines. Some time afterwards another embassy, of whose purpose we are not informed, arrived at Ravenna, and Constantine promised to assist his colleague Honorius against Alaric, who was threatening Rome. Perhaps what Honorius was to do in return for the proffered assistance was to permit the sovran of Gaul to assume the consulship. In any case it was suspected that Constantine aspired to add Italy to his realm as he had added Spain, and that the subjugation of Alaric was only a pretext for entering Italy, as it might have been said that the subjugation of the Vandals and their fellow-invaders had been only a pretext for his entering Gaul. Hellebich, Master of Soldiers (equitum), was also suspected of favouring the designs of the usurper, and the suspicion, whether true or false, cost him his life; Honorius caused him to be assassinated. When this occurred Constantine was already in Italy, and the fact that when the news reached him he immediately recrossed the mountains, strongly suggests that the suspicion was true, and that he depended on this general’s treason for the success of his Italian designs.
Constans had left his general, Gerontius, a Briton, in charge of Spain. Barbarian federates, known as Honorians, had been used for the conquest of Spain by Constans, and to these was entrusted the defence of the passes of the Pyrenees. It was an unfortunate measure. The Spanish regular troops, who now acknowledged the authority of Constantine, thought that the charge ought to have been entrusted as before to the national militia, and they revolted.50 The Honorians betrayed or neglected their trust. It was the autumn of A.D. 409, and on a Tuesday, either September 28 or October 5, the host of barbarians who had been oppressing western Gaul for more than two years — the Asdings under King Gunderic, the Silings, the Sueves, and the Alans — crossed the mountains and passed into Spain.51
Constans imputed the troubles in Spain to the incapacity of Gerontius, and he returned from Gaul to supersede him and restore order. But Gerontius was not of a spirit to submit tamely. He seems to have come to terms with the legions, and he made some sort of league with the barbarians, by which a large part of the land was abandoned to them.52 He renounced the authority of Constantine, and though he did not assume the purple himself, he raised up a new Emperor, a certain Maximus, who was perhaps his own son.
Thus at the beginning of A.D. 410 there were six Emperors, legitimate and illegitimate, acknowledged in various parts of the Empire. Besides Honorius and his nephew Theodosius, there was Attalus at Rome, there were Constantine and Constans at Arles, and there was Maximus at Tarragona.
Constans soon fled before Gerontius and his barbarian allies to Gaul, and after some time — the chronology is very obscure — Gerontius, leaving Maximus to reign in state at Tarragona, marched into Gaul against the father and son who had once been his masters. It was apparently in A.D. 411 that Constans was captured and put to death at Vienne, and then his father Constantine was besieged at Arles.
But Honorius, now that Alaric was dead, although the Goths were still in Italy, was able to bethink him of the lands he had lost beyond the Alps, and he sent an army under two generals Constantius and Ulfila, to do what Sarus had failed to do and win back Gaul. Constantius was an Illyrian, born at Naissus, the birthplace of Constantine the Great, and for the next ten years the fortunes of Honorius were to depend upon him as before they had depended upon Stilicho. We may consider it certain that when he led the troops of Italy to Gaul he had already been raised to the post of Master of Both Services.53 We have a slight portrait of his appearance and manners. He had large eyes, a broad head, and a long neck; he leaned low over the