BAYEZID I  . (1347-1403),

Ottoman sultan, surnamed YILDERIM or " LIGHTNING," from the great rapidity of his movements, succeeded his father Murad I. on the latter's assassination on the field of Kossovo, 1389, and signalized his accession by ordering at once the execution of his brother Yakub, who had distinguished himself in the battle . His arms were successful both in Europe and Asia, and he was the first Ottoman sovereign to be styled " sultan," which title he induced the titular Abbasid caliph to confer on him . After routing the chivalry of Christendom at the battle of Nikopoli in 1396, he pursued his victorious career in Greece, and Constantinople would doubtless have fallen before his attack, had not the emperor Manuel Palaeologus bought him off by timely concessions which reduced him practically to the position of Bayezid's vassal . But his conquests met with a sudden and overpowering check at the hands of Timur (Tamer-lane) . Utterly defeated at Angora by the Mongol invader, Bayezid became his prisoner, and died in captivity some months later, in March 1403 . Bayezid first married Devlet Shah Khatun, daughter of the prince of Kermian, who brought him in dowry Kutaiah and its dependencies . Two years before his accession he also married a daughter of the emperor John Palaeologus .