Demótica
Demótica, known to the Greeks as Didymoteichon and to the Ottomans as Dimetoka, stands near the Hebrus in Thrace. Its name means “twin wall,” recalling the fortifications that guarded a town of considerable importance to Byzantine emperors. Below the hilltop citadel, the great mosque of Çelebi Sultan Mehmed bears witness to its later Ottoman rulers.
In October 1341 John Kantakouzenos was proclaimed emperor at Didymoteichon, beginning a bitter civil war against the regency of John V Palaiologos. The town served as his headquarters during the struggle. After the Ottoman conquest, it continued to attract imperial patronage. Sultan Mehmed I ordered the construction of a large mosque whose entrance inscription records the year 1420. Its monumental prayer hall and timber roof made it one of the most imposing buildings of the early Ottoman town.