Constantine acted with the extreme rapidity for which he was already famous. He hurried his army down from the Rhine, and was through the passes and attacking the walled city of Susa before Maxentius had certain knowledge of his movements. That he was embarking on an exceedingly hazardous expedition seems to have been recognised by himself and his captains. The author of the Ninth Panegyric says quite bluntly that his principal officers not only muttered their fears in secret, but expressed them openly,[41] and adds that his councillors and haruspices warned him to desist. A similar campaign had cost Severus his life and had been found too hazardous even by Galerius. Superiority of numbers lay not with him, but with his rival. Constantine was gravely handicapped by the fact that he had to safeguard the Rhine behind him against the Germanic tribes, which he knew would seize the first opportunity to pass the river. Zosimus gives a detailed account[42] of the numbers which the rivals placed in the field. Maxentius, he says, had 170,000 foot and 18,000 horse under his command, including 80,000 levies from Rome and Italy, and 40,000 from Carthage and Africa. Constantine, on the other hand, even after vigorous recruiting in Britain and Gaul, could only muster 90,000 foot and 8000 horse. The author of the Ninth Panegyric, in a casual phrase, says that Constantine could hardly employ a fourth of his Gallic army against the 100,000 men in the ranks of Maxentius, on account of the dangers of the Rhine. Ancient authorities, however, are never trustworthy where numbers are concerned; we only know that Maxentius had by far the larger force, and that Constantine’s army of invasion was probably under 40,000 strong. Whether the numerical supremacy of the former was not counterbalanced by the necessity under which Maxentius laboured of guarding against Licinius, is a question to which the historians have paid no heed. ----- Footnote 41: _Non solum tacite mussantibus sed eteiam aperte timentibus._—_Pan. Vet._, ix., 2. Footnote 42: Zosimus, ii., 15. -----