In the second year of his reign, after he had arranged a suitable _status quo_ with the Serbians of upper Macedonia, Bayezid began that policy of aggrandizement in Asia Minor which led finally to his downfall. His first encroachment was against Isa bey of Aïdin. Isa was too weak to oppose Bayezid single-handed. Instead of seeking to ally the independent emirs against the Osmanlis, Isa thought he could save himself with less risk by becoming a vassal of Bayezid. He was compelled to give up Ayasoluk, and make Tyra his capital. Bayezid almost immediately broke faith with Isa, and exiled him to Brusa or Nicaea, where he died.[446] His two sons, Isa and Omar, managed to escape to the court of Timur, who was rapidly becoming the most powerful Moslem ruler in Asia. The occupation of Ephesus aroused momentarily Bayezid’s ambition to take possession of Smyrna. In 1391, he did in fact make some efforts to overpower the garrison, which was greatly weakened by pestilence.[447] Later he occupied the passes around Smyrna to prevent the entrance of provisions.[448] But Smyrna, like Constantinople, could not be starved out so long as the Osmanlis were not masters of the sea. Bayezid never pressed this mild form of siege to a definite assault. His hands were too full elsewhere. An unsuccessful assault against Smyrna would have destroyed his prestige in the new territory of Aïdin, which was not any too securely his by the suppression of its ruling family. Perhaps, also, he realized that Smyrna, more than any other place in the Levant except Rhodes, had become the city of promise to the Roman Church. He did not want to stir up an active resistance on the part of the chevaliers of Rhodes, for they might easily be induced to lend aid to the emirs whom he was destroying. Sarukhan and Menteshe, during the reign of Murad, had lost the most virile element of their population in corsair expeditions. The Turks of whom one reads as the roving and raiding adventurers in the Aegaean and Mediterranean during the fourteenth century were largely from these emirates. Decades of outgo without a corresponding income in fighting men so depleted the maritime emirates that they were not in a position to withstand Bayezid as they had done his father and grandfather. Their population was seafaring, and their princes were traders rather than warriors. When the armies of Bayezid invaded Sarukhan and Menteshe, the two emirs attempted no resistance. They took refuge with Bayezid, emir of Kastemuni, and abandoned their emirates to the Osmanlis.[449]