Bayezid next turned his attention to Asia Minor, where he was mainly ambitious to add to his Empire. His first effort there was directed against Aidin. After defeating its Emir and annexing the State, he dealt in the same way with the Emirs of Sarukhan and Mentsche. He then made an attack on the city of Smyrna, at that time in possession of the Knights of St. John of Jerusalem. The Knights made a vigorous resistance, and Bayezid, not having command of the sea, was compelled, after six weeks, to withdraw from the siege. He next, in 1391, attacked the Emir of Tekke, and took from him what had been left under his rule by Murad, including the important city of Adalia. The Ottoman frontier was now conterminous with that of Karamania, whose Emir, Alaeddin, was brother-in-law to the Sultan. This family connection was no protection to him. Bayezid invaded and laid siege to Konia. He withdrew on Alaeddin agreeing to give up a slice of his Emirate, including the city of Ak-Sheir. Having achieved these annexations, for which there was no justification other than mere greed for the extension of his Empire, Bayezid returned to Adrianople, leaving his general, Timurtash, in command of the conquered provinces. The Greek Emperor John, meanwhile, had been engaged in putting his capital into a state of defence, and for this purpose had demolished three of the most beautiful churches of Constantinople, intending to use their masonry for the erection of new forts. The Sultan, when he heard of this, sent word to the Emperors ordering them to desist from any such work, and threatening to deprive Manuel of his eyesight. The Emperor had no alternative but to obey. But this humiliation was the last he had to endure. He died very shortly afterwards, under the weight of his cares and anxieties, as some historians say, but according to others of gout and debauchery. His son, Manuel, who was detained at the Court of the Sultan, acting as a kind of Groom of the Chamber, on hearing of his father’s death, secretly fled and reached Constantinople, where he was installed as the successor to his father. Bayezid by way of reprisal for this directed a blockade by land of Constantinople. There commenced what was virtually a siege by land of the city, which lasted for seven years, till the invasion of Asia Minor by Timur caused a diversion and brought it to an end.