During the ensuing winter, on account of the scarcity of provisions, the Roman troops had to be quartered in separate detachments at long distances. One of these was treacherously destroyed by the Gauls, and the others were saved only by the extraordinary quickness with which Cæsar marched to their relief on hearing of their imminent danger. The chief part in this rising had been taken by the Eburones, led by their king Ambiorix. A large part of the sixth book is occupied with the recital of Cæsar's vengeance upon these people and their abettors, and with the vain pursuit of Ambiorix. The remainder contains an elaborate contrast of the manners and customs of the Gauls and Germans, which forms an important source for the history of the primitive institutions of these nations. The seventh book is the thrilling tale of the formidable rising of all the Gauls against their conquerors, under the leadership of Vercingetorix, an Arvernian chief. This man was a real hero,--brave, patriotic, resourceful, perhaps the only worthy antagonist that Cæsar ever met. This war strained to the utmost Cæsar's abilities and the disciplined valor of his legions. The Gauls nearly succeeded in undoing all the work of six years, in destroying the Roman army and in throwing off the Roman yoke. In this campaign, more conspicuously than ever before, Cæsar's success was due to the unexampled rapidity of his movements. So perfect had become the training of his troops and their confidence in his ability to win under all circumstances, that after a campaign of incredible exertions they triumphed over the countless hosts of their gallant foes, and in the next two years the last embers of Gaulish independence were finally stamped out. In all his later wars, Cæsar never had anything to fear from Gaul. As we read the story of Avaricum, of Gergovia, of Alesia, our sympathy goes out to the brave barbarians who were fighting for liberty--but we have to remember that though the cause of freedom failed, the cause of civilization triumphed. The eighth book, containing the account of the next two years, 51 and 50 B.C., was written by one of Cæsar's officers, Aulus Hirtius.