The House of Dejanović (Serbian Cyrillic: Дејановић, pl. Dejanovići / Дејановићи) or House of Dragaš (Serbian Cyrillic: Драгаш, pl. Dragaši / Драгаши) originates from a medieval noble family that served the Serbian Empire of Dušan the Mighty (r. 1331–1355) and Uroš the Weak (r. 1355–1371), and during the fall of the Serbian Empire, after the Battle of Maritsa (1371), it became an Ottoman vassal. The family was one of the most prominent during these periods. The Dejanović/Dragaš held a region roughly centered where the borders of Serbia, Bulgaria and North Macedonia meet. The last two Byzantine Emperors were maternal descendants of this house.
The progenitor, sevastokrator Dejan, was a magnate in the service of Emperor Dušan, and also the Emperor's brother-in-law through his marriage with Teodora-Evdokija. Dejan held the župe (counties) of Žegligovo and Preševo under Dušan, and later received the title of despot during the rule of Dušan's son, Emperor Uroš V, when he was appointed the administration Upper Struma with Velbužd, after the death of powerful despot Jovan Oliver. After Dejan's death between 1358 and 1365, most of his province was given to Vlatko Paskačić, besides the initial counties of Žegligovo and Preševo, which were left to his two sons, Jovan and Konstantin. The brothers, who ruled jointly, managed to double the extent of their province during the Fall of the Serbian Empire following Emperor Uroš V's death, chiefly to the south; the lands now covered from Vranje and Preševo to Radomir, in the south to Štip, Radovište and Strumica. In 1373, two years after the devastating Battle of Maritsa, the brothers became vassals to the Ottoman Empire. After the death of Jovan in 1377, Konstantin continued to rule under Ottoman overlordship. Konstantin and his provincial neighbour and fellow Ottoman vassal, Prince Marko, fell at the Battle of Rovine in 1395.
