Stephen Dušan was succeeded by his son, known as Tsar Uroš, but he was as weak as his father had been strong. Almost as soon as he succeeded to the throne, disorders, rebellions, and dissensions broke out and the empire rapidly fell to pieces. With Serbia, as with Bulgaria, the empire entirely hinged on the personality of one man, and when he was gone chaos returned. Such an event for Serbia at this juncture was fatal, as a far more formidable foe than the ruler’s rebellious relations was advancing against it. The Turkish conquests were proceeding apace; they had taken Gallipoli in 1354 and Demotika and Adrianople in 1361. The Serbs, who had already had an unsuccessful brush with the advance guard of the new invaders near Demotika in 1351, met them again on the Maritsa river in 1371, and were completely defeated. Several of the upstart princes who had been pulling Stephen Dušan’s empire to pieces perished, and Tsar Uroš only survived the battle of the Maritsa two months; he was unmarried, and with him died the Nemanja dynasty and the Serbian Empire. After this disaster the unity of the Serbian state was completely destroyed, and it has never since been restored in the same measure. That part of the country to the south of Skoplje fell completely under Turkish control; it was here that the famous national hero, Marko Kraljević (or King’s son), renowned for his prowess, ruled as a vassal prince and mercenary soldier of the Turks; his father was one of the rebel princes who fell at the battle of the river Maritsa in 1371. North of Skoplje, Serbia, with Kruševac as a new political centre, continued to lead an independent but precarious existence, much reduced in size and glory, under a native ruler, Prince Lazar; all the conquests of Stephen Dušan were lost, and the important coastal province of Zeta, which later developed into Montenegro, had broken away and proclaimed its autonomy directly after the death of Tsar Uroš. In 1375 a formal reconciliation was effected with the Patriarch of Constantinople; the ban placed on the Serbian Church in 1352 was removed and the independence of the Serbian Patriarchate of Peć (Ipek) recognised. Meanwhile neither Greeks, Bulgars, nor Serbs were allowed any peace by the Turks.