Caesar (19.4-19.5)

Still more, too, was the spirit of the Germans blunted by the prophecies of their holy women, who used to foretell the future by observing the eddies in the rivers and by finding signs in the whirlings and splashings of the waters, and now forbade joining battle before a new moon gave its light. When Caesar learned this, and saw that the Germans kept quiet, he decided that it was a good plan to engage them while they were out of heart, rather than to sit still and wait for their time.

So, by attacking their entrenchments and the hills on which they were encamped, he irritated them and incited them to come down in anger and fight the issue out. They were signally routed, and Caesar pursued them a distance of four hundred furlongs, as far as the Rhine, and filled all the intervening plain with dead bodies and spoils. Ariovistus, with a few followers, succeeded in crossing the Rhine; his dead are said to have been eighty thousand in number.