But, unfortunately, the character of the young emperor, weakened by the subjection in which his mother had kept him, was utterly inadequate to the duties of his new position. With extraordinary folly, after a few months he drew Irene forth from the seclusion of her palace, and allowed the people to shout once more, “Long life to Constantine and Irene.” He went forth to war with the Bulgarians and was badly beaten. This humiliation of the imperial arms caused the soldiers in the city to plot for the elevation of Nicephorus, a half-brother of Leo IV. and uncle of Constantine VI. The young emperor arrested Nicephorus and ordered him to be blinded; and at the same time the tongues of four other of his uncles were cut out (792). These barbarous punishments, blinding and mutilation, were characteristic of the Constantinople of that day, but the resort to them on so large a scale proved the alarm as well as the cruelty of the young emperor, and must have helped to lose him the hearts of his subjects. His mother and Stauracius (who was now back again in the palace) were thought to have counselled these cruel deeds; and they certainly succeeded in embroiling him with his old supporters, the Armenian soldiers, whose revolts plunged the empire in civil war.
The climax of the emperor’s unpopularity seems to have been reached when (in January 795) he put away his Armenian wife, compelling her to enter a convent, and in September of the same year publicly celebrated his union with a lady of her bedchamber named Theodote. He had now lost the favor of the multitude, while his mother was ever at work forming a party among the officers by promises and bribes, suggesting that they should depose her son and proclaim her sole empress. On the 14th of June 797 Constantine went, after witnessing an equestrian performance in the circus, to worship in the church of St. Mamas in the environs of Constantinople. The conspirators, whose movements were directed by Stauracius, endeavored to seize him there, but he seems to have been warned, and escaped in the imperial boat to the Bithynian shore. Unhappily his mother’s friends and his own bitterest foes accompanied his flight. There was hesitation and delay, and there seemed a possibility that the soldiers would rally round him and his cause might yet triumph. The ruthless Irene sent a secret message to his adherents, “Unless in some way or other you effect his capture I will inform the emperor of all the plot which you and I have formed against him.” Fear made the conspirators bold; they seized the emperor while at his prayers, forced him to re-embark, and hurried him back across the Sea of Marmora to Constantinople. There, after the lapse of some weeks, in the Purple Chamber of the palace, they put out his eyes, purposely performing the cruel operation with such brutality as to endanger his life. It was, in fact, supposed by many that he was dead, but he appears to have lingered on through many revolutions, an obscure and forgotten sufferer, for more than twenty years after his mutilation.