MARITSA RIVER, BATTLE OF THE

(Sept. 26, 1371), Ottoman Turk victory over Serbian forces that allowed the Turks to extend their control over southern Serbia and Macedonia. After the Ottoman sultan Murad I (reigned 136089) advanced into Thrace, conquered Adrianople, and thereby gained control of the Maritsa River valley, which led into the central Balkans, the Christian states of the Balkans formed an alliance to drive him back. Their early efforts ended in defeat, and the Bulgarians were compelled to become vassals of the sultan (1366). Another campaign to resist Turkish expansion was organized in 1371 by Vukain, the king of the southern Serbian lands, who gathered an army of 70,000 men and marched into the Maritsa valley. While halting at Chernomen (Chirmen; located between Philippopolis and Adrianople), however, his forces were surprised by a much smaller Turkish army, which slaughtered large numbers of Serbs, including Vukain, and drove many of the survivors into the river to be drowned. The battle involved such carnage that the field was later referred to as the Serbs' destruction. It confirmed Bulgaria's status as a vassal-state to the Turks and destroyed the independent South Serbian kingdom, whose new ruler, Marko Kraljevic, became a vassal of the sultan. Macedonia and ultimately the remainder of the Balkan Peninsula were exposed to Turkish conquest.