cum exercitum duceret, et inscio ipso manus auxiliaria centurionibus suis auctoribus tria milia Sarmatarum neglegentius agentum in Danuvii ripis occidissent et cum praeda ingenti ad eum redissent sperantibus centurionibus praemium, quod perparva manu tantum hostium segnius agentibus tribunis et ignorantibus occidissent, rapi eos iussit et in crucem tolli servilique supplicio adfici, quod exemplum non exstabat, dicens evenire potuisse ut essent insidiae, ac periret Romani imperii reverentia.
Translation :
Once when he was commanding the army, a band of auxiliaries, at the suggestion of their centurions and without his knowledge, slaughtered 3,000 Sarmatians, who were camping somewhat carelessly on the bank of the Danube, and returned to him with immense plunder. But when the centurions expected a reward because they had slain such a host of the enemy with a very small force while the tribunes were passing their time in indolence and were even ignorant of the whole affair, he had them arrested and crucified, and punished them with the punishment of slaves, for which there was no precedent; "It might," he said, "have been an ambush, and the barbarians' awe for the Roman Empire might have been lost."
Edition :
Historia Augusta, Volume I: Hadrian. Aelius. Antoninus Pius. Marcus Aurelius. L. Verus. Avidius Cassius. Commodus. Pertinax. Didius Julianus. Septimius Severus. Pescennius Niger. Clodius Albinus. Translated by David Magie. Loeb Classical Library 139. Cambridge, MA: Harvard University Press, 1921.
Notes :
For the preceding successful ambush, please refer to: "Auxiliary soldiers ambush and kill 3000 Sarmartians on their centurion’s initiative."