The Roman History · Amm. 16.12.17

Moreover there was another circumstance which at this crisis added weight to the difficulties which pressed upon the Romans. The two royal brothers, who had obtained peace from Constantius in the preceding year, being bound by the obligations of that treaty, neither ventured to raise any disturbance, nor indeed to put themselves in motion at all. But a little after the conclusion of that peace one of them whose name was Gundomadus, and who was the most loyal and the most faithful to his word, was slain by treachery, and then all his tribe joined our enemies; and on this the tribe of Vadomarius also, against his will, as he affirmed, ranged itself on the side of the barbarians who were arming for war.

Ammianus Marcellinus · translated by C. D. Yonge · 1911 reprint
C. D. Yonge translation (preface dated February 1862); G. Bell and Sons, 1911; Project Gutenberg #28587
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