The spring was now approaching, and the time for military operations on a grand scale drew near. Chosroes, besides his supporters in Mesopotamia, Roman and Persian, had a second army in Azerbijan, raised by his uncles Bindoes and Bostam, which was strengthened by an Armenian contingent. The plan of campaign involved the co-operation of these two forces. With this object Chosroes proceeded early in the spring, from Hierapolis to Constantina, from Constantina to Daras, and thence by way of Ammodion to the Tigris, across which he sent a detachment, probably in the neighborhood of Mosul. This force fell in with Bryzacius, who commanded in these parts for Bahram, and surprising him in the first watch of the night, defeated his army and took Bryzacius himself prisoner. The sequel, which Theophylact appears to relate from the information of an eye-witness, furnishes a remarkable evidence of the barbarity of the times. Those who captured Bryzacius cut off his nose and his ears, and in this condition sent him to Chosroes. The Persian prince was overjoyed at the success, which no doubt he accepted as a good omen; he at once led his whole army across the river, and having encamped for the night at a place called Dinabadon, entertained the chief Persian and Roman nobles at a banquet. When the festivity was at its height, the unfortunate prisoner was brought in loaded with fetters, and was made sport of by the guests for a time, after which, at a signal from the king, the guards plunged their swords into his body, and despatched him in the sight of the feasters. Having amused his guests with this delectable interlude, the amiable monarch concluded the whole by anointing them with perfumed ointment, crowning them with flowers, and bidding them drink to the success of the war. "The guests," says Theophylact, "returned, to their tents, delighted with the completeness of their entertainment, and told their friends how handsomely they had been treated, but the crown of all (they said) was the episode of Bryzacius."
Chosroes next day advanced across the Greater Zab, and, after marching four days, reached Alexandrian a position probably not far from Arbela, after which, in two days more, he arrived at Chnaethas, which was a district upon the Zab Asfal, or Lesser Zab River. Here he found himself in the immediate vicinity of Bahram, who had taken up his position on the Lesser Zab, with the intention probably of blocking the route up its valley, by which he expected that the Armenian army would endeavor to effect a junction with the army of Chosroes. Here the two forces watched each other for some days, and various manoeuvres were executed, which it is impossible to follow, since Theophylact, our only authority, is not a good military historian. The result, however, is certain. Bahram was out-manoeuvred by Chosroes and his Roman allies; the fords of the Zab were seized; and after five days of marching and counter-marching, the longed-for junction took place. Chosroes had the satisfaction of embracing his uncles Bindoes and Bostam, and of securing such a reinforcement as gave him a great superiority in numbers over his antagonist.