capturing the towns of Lykostomion and Kastrion, he faltered before Servia, which was defended by Preljub himself. Kantakouzenos withdrew, and Lykostomion and Kastrion were recovered by the Serbs soon after. Preljub's rule is otherwise obscure, except for his reaching an agreement with the local Albanian tribes; an agreement that probably did not last long, for he was killed in a clash with them. The death of Preljub was preceded by that of Dushan himself, leaving a power vacuum in the wider Serbian Empire and in Thessaly in particular. In this context, Nikephoros Orsini, the exiled son of John II Orsini, who had entered Byzantine service, tried to realize his ancestral claims over the region. From Ainos, he sailed to Thessaly, which he captured quickly, expelling Preljub's wife and son. He then conquered Aetolia, Acarnania, and Leukas. Catalan control over southern Thessaly had ceased by this time. Nikephoros came into conflict with the Albanians, however, and was killed in the Battle of Achelous in 1359. Following Nikephoros' death, Thessaly was taken over without resistance by Dushan's half-brother Simeon Uroš. Enjoying the support of the local Greek and Serbian nobility, Simeon Uroš reigned as self-proclaimed emperor from Trikala until his death in 1370. He was particularly noted as a patron of the Meteora monasteries, who regarded him as their "second founder". His son John Uroš succeeded him until 1373, when he retired to a monastery; Thessaly was then ruled by Alexios Angelos Philanthropenos and (from ) Manuel Angelos Philanthropenos, who recognized Byzantine suzerainty until , when the region was conquered by the Ottoman Empire. In the south, the Florentine adventurer Nerio Acciaioli had managed to take over the Duchy of Athens from the Catalans, and in 1390 captured Neopatras as well. These territories were soon lost to the Ottoman Turks, at about the same time as the fall of Thessaly. Ottoman period The Ottomans first invaded Thessaly in 1386, when Gazi Evrenos took Larissa for a time, confining the Angeloi Philanthropenoi to their holdings in western Thessaly, around Trikala. In ca. 1393, the second phase of the invasion began, again under Evrenos. The Ottomans defeated Manuel Angelos Philanthropenos, and retook Larissa. The conquest of Thessaly was completed during the next few years, from 1394 under the personal supervision of Sultan Bayezid I. The fortresses of Volos, Pharsalus, Domokos and Neopatras were taken, and in 1395/6, Trikala too fell. After the disastrous Battle