The Roman History · Amm. 21.13.3

However, not to lose time, and to avoid inactivity, he sent Arbetio and Agilo, the captains of his infantry and cavalry, with very large forces, to march with all speed; not to provoke the Persians to battle, but to establish forts on the nearest bank of the Tigris, which might be able to reconnoitre, and see in what direction the furious monarch broke forth; and with many counsels given both verbally and in writing, he charged them to retreat with celerity the moment the enemy's army began to cross the river.

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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