Charles’s reply to this direct attack on his dominions in the south of Italy was to lay hands on the Imperial province of Istria in the north, a conquest desirable in itself, for the cities of Istria were numerous and wealthy, and also one that facilitated the operations which he was planning against the Avars. The Court of Constantinople, probably dispirited by the defeat of the great armament under the _sacellarius_ John seems to have accepted the rebuff. For several years after this we hear nothing more of Greek expeditions to Italy, though there may have been intrigues with the young Prince of Benevento, who married a Greek wife named Wantia, a relative of the Emperor, and in various ways showed that he fretted under his galling vassalage to the Frankish king. But in Constantinople itself during these years of truce with the West, strange and terrible events were happening. The young Emperor Constantine VI. found as he grew up to manhood that he was an absolute cipher in his empire and in his palace. All power was kept by Irene in her own hands, all orders went through her confidential minister the eunuch Stauracius. To these two all suppliants dressed their petitions. Constantine himself was treated as of no account to any man. Brooding over the daily slights which he had to endure, and resenting also, it is said, the manœuvre which had deprived him of his fair young Frankish bride, and tied him to the unloved and childless Armenian, he began in 790 to look around for partizans who would enable him to effect a revolution and become a real instead of a puppet emperor. The plan of the conspirators (among whom were two patricians and the great minister called _magister officiorum_), was to arrest the empress, send her off to banishment in Sicily, and proclaim Constantine sole emperor. The ever watchful Stauracius, however, obtained intelligence of the plot, arrested the conspirators, ordered some of them to be flogged, tonsured, and sent into the Sicilian exile which they had planned for Irene; the _magister officiorum_ received some degrading punishment and was imprisoned in his own house; and lastly this same punishment of seclusion was inflicted on Constantine, after his mother had herself struck him and attacked him with an angry woman’s invective. Then a new and strange oath was administered to all the soldiers in the capital and its neighborhood. “So long as thou livest, O Empress! we will not suffer thy son to reign.” These events took place in the spring or summer of 791. In September of that year there came a change. The soldiers who were stationed in Armenia, when they were required to take the new oath, refused. “We will not put the name of Irene before that of Constantine,” said they, “but will swear obedience as of old to Constantine and Irene.” The disaffection spread; the regiments which had sworn the new oath to Irene forgot their vows and joined the soldiers from Armenia. By the end of October the revolution was complete.