The retreat of Chosroes may be ascribed with much probability to the advance of another danger, more formidable than Belisarius, which exactly at this time made its appearance in the country whereto he was hastening. It was in the summer of A.D. 542 that the plague broke out at Pelusium, and spread from that centre rapidly into the rest of Egypt and also into Palestine. Chosroes may well have hesitated to confront this terrible foe. He did not ultimately escape it; but he might hope to do so, and it would clearly have been the height of imprudence to have carried out his intention of invading Palestine when the plague was known to be raging there. The fourth year of the Roman war (A.D. 543) opened with a movement of the Persian troops toward the Armenian frontier, consequent upon the desertion of the Persian cause by the Roman Armenians in the course of the winter. Chosroes in person once more led the attack, and proceeded as far as Azerbijan; but, the pestilence breaking out in his army, he hastily retreated, after some futile attempts at negotiation with the Roman officers opposed to him. Belisarius had this year been sent to Italy, and the Roman army of the East, amounting to thirty thousand men, was commanded by as many as fifteen generals, almost of equal rank, among whom there was little concert or agreement. Induced to take the offensive by the retirement of the Persian king, these incapable officers invaded Persarmenia with all their troops, and proceeded to plunder its rich plains and fertile valleys. Encountering suddenly and unexpectedly the Persian general Nabedes, who, with a small force, was strongly posted at a village called Anglon, they were compelled to engage at disadvantage; their troops, entangled in difficult ground, found themselves attacked in their rear by an ambush; Narses, the bravest of them, fell; and, a general panic seizing the entire multitude, they fled in the extremest disorder, casting away their arms, and pressing their horses till they sank and expired. The Persians pursued, but with caution, and the carnage was not so great as might have been expected; but vast numbers of the disarmed fugitives were overtaken and made prisoners by the enemy; and the arms, animals, and camp equipment which fell into the hands of the Persians amply compensated all previous losses, and left Persarmenia the richer for the inroad.