Res Gestae
Ammianus Marcellinus
Ammianus Marcellinus. Ammianus Marcellinus, with an English translation, Vols. I-III. Rolfe, John C., translator. Cambridge, MA; London: Harvard University Press; W. Heinemann, 1935-1940 (printing).
But quicker than a flash he followed them up after their departure, and sending his general Severus along the river bank, fell upon the whole troop suddenly and smote them like a thunderstorm; at once they took to entreaties rather than to resistance, and he turned the outcome of his victory into the timely direction of mercy by receiving them in surrender with their property and their children.