Plutarch, Caesar
Bernadotte Perrin, Ed.

22. On returning to his forces in Gaul,¹ Caesar found a considerable war in the country, since two great German nations had just crossed the Rhine to possess the land, one called the Usipes,² the other the Tenteritae. [2] Concerning the battle which was fought with them Caesar says in his ‘ Commentaries ’ ³ that the Barbarians, while treating with him under a truce, attacked on their march and therefore routed his five thousand cavalry with their eight hundred, since his men were taken off their guard; that they then sent other envoys to him who tried to deceive him again, but he held them fast and led his army against the Barbarians, considering that good faith towards such faithless breakers of truces was folly. [3] But Tanusius says that when the senate voted sacrifices of rejoicing over the victory, Cato pronounced the opinion that they ought to deliver up Caesar to the Barbarians, thus purging away the violation of the truce in behalf of the city, and turning the curse therefor on the guilty man.

Of those who had crossed the Rhine into Gaul four hundred thousand were cut to pieces, and the few who succeeded in making their way back were received by the Sugambri, a German nation. [4] This action Caesar made a ground of complaint against the Sugambri, and besides, he coveted the fame of being the first man to cross the Rhine with an army. He therefore began to bridge the river,⁴ although it was very broad, and at this point in its course especially swollen, rough, and impetuous, and with the trunks and branches of trees which it bore down stream kept smiting and tearing away the supports of his bridge. But Caesar caught up these trunks and branches with bulwarks of great timbers planted across the stream, and having thus bridled and yoked the dashing current, he brought his bridge—sight beyond all credence—to completion in ten days.