a Roman general, legate of the first legion of the army on the Rhine (A. D. 69) was stationed at Bonn when the Batavian insurrection broke out, and was ordered by Hordeonius Flaccus to prevent some Batavian cohorts, which had deserted from the Romans, from uniting with Civilis. Hordeonius recalled his commands, but Gallus was compelled by his own soldiers to fight, and was defeated through the fault of his Belgic auxiliaries. He was afterwards associated with Vocula in the command, after the deposition of Hordeonius, and was in command of the camp at Gelduba when a trifling accident excited a mutiny among his soldiers, who scourged and bound him; but he was released by Vocula. When Vocula was killed at Novesium, Herennius was only bound. He was afterwards killed by Valentinus and Tutor, A. D. 70. [CIVILIS; VOCULA ; VALENTINUS]. (Tac. Hist. 4.19, 20, 26, 27, 59, 70, 77.)