Saint Isaac, the Monk, predicts the Death of Valens. Valens in his Flight enters a Chaff-House, is consumed, and so yields up his Life
When Valens was on the point of departing from Constantinople, Isaac, a monk of great virtue, who feared no danger in the cause of God, presented himself before him, and addressed him in the following words: “Give back, O emperor, to the orthodox, and to those who maintain the Nicene doctrines, the churches of which you have deprived them, and the victory will be yours.” The emperor was offended at this act of boldness, and commanded that Isaac should be arrested and kept in chains until his return, when he meant to bring him to justice for his temerity.
Isaac, however, replied, “You will not return unless you restore the churches.” And so in fact it came to pass. For when Valens marched out with his army, the Goths retreated while pursued. In his advances he passed by Thrace, and came to Adrianople. When at not great distance from the barbarians, he found them encamped in a secure position; and yet he had the rashness to attack them before he had arranged his own legions in proper order. His cavalry was dispersed, his infantry compelled to retreat; and, pursued by the enemy, he dismounted from his horse, and with a few attendants entered into a small house or tower, where he secreted himself.
The barbarians were in full pursuit, and went beyond the tower, not suspecting that he had selected it for his place of concealment. As the last detachment of the barbarians was passing by the tower, the attendants of the emperor let fly a volley of arrows from their covert, which immediately led to the exclamation that Valens was concealed within the building. Those who were a little in advance heard this exclamation, and made known the news with a shout to those companions who were in advance of them; and thus the news was conveyed till it reached the detachments which were foremost in the pursuit.
They returned, and encompassed the tower. They collected vast quantities of wood from the country around, which they piled up against the tower, and finally set fire to the mass. A wind which had happened to arise favored the progress of the conflagration; and in a short period the tower, with all that it contained, including the emperor and his attendants, was utterly destroyed. Valens was fifty years of age. He had reigned thirteen years conjointly with his brother, and three by himself.
Source: Ecclesiastical History (New Advent)