Zosimus, New History 3.24
Zosimus (Greek Ζώσιμος): Early Byzantine, pagan author of a history of the Roman Empire, published in the first quarter of the sixth century CE.
The translation of Zosimus' New History offered here was printed in 1814 by W. Green and T. Chaplin in London, and was probably prepared by J. Davis of the Military Chronicle and Military Classics Office. The translator is anonymous. The text was found at Tertullian.org. The notes were added by Jona Lendering.
[3.24.1] Soon after his execution, the army marched to Arintheus, and searching all the marshes found in them many people whom they made prisoners. Here it was that the Persians first collected their forces, and attacked the advanced party of the Roman army. They were however routed, and preserved their lives by flying to a neighboring city. The Persians on the other side of the river attacked the slaves who had the care of the beasts of burden, and those who guarded them; they killed part of them and made the rest prisoners. This being the first loss which the Romans had sustained occasioned some consternation in the army.
[3.24.2] They advanced to a very broad sluice or channel, said by the country people to have been cut by Trajan, when he made an expedition into Persia. In this channel runs the river Narmalaches,note[The nār šarri or Naarmalcha, "royal river", connected the Euphrates and Tigris; cf. Zosimus, New History 3.19.3.] and discharges itself into the Tigris. The emperor caused it to be cleansed, in order to enable his vessels to pass through it into the Tigris, and constructed bridges over it for the passage of his army.