John Doukas

John Doukas, Latinized as Ducas is the name of several Byzantine aristocrats and their descendants. It may refer to any of the following:


 * John Doukas (Caesar) (fl. 1074–1088), brother of Emperor Constantine X Doukas
 * John Doukas (megas doux) (c. 1064 – before 1136), brother-in-law of Alexios I Komnenos
 * John Doukas (megas hetaireiarches) (fl. 1155–1181), military commander and diplomat
 * John Doukas (sebastokrator) (c. 1126), cousin of Emperors Isaac II Angelos and Alexios III Angelos
 * John Doukas Komnenos (1128–1176)
 * John III Doukas Vatatzes (1193–1254), Emperor of Nicaea 1222–1254
 * John Komnenos Doukas (d. 1244), ruler of Thessalonica and Thessaly 1237–1244
 * John Doukas (son of Michael II), son of Michael II of Epirus, hostage in Constantinople
 * John I Doukas of Thessaly, ruler of Thessaly 1268–1289
 * John II Doukas of Thessaly, ruler of Thessaly 1303–1318
 * John II Orsini (also called Doukas), ruler of Epirus 1323–1335
 * John Uroš, ruler of Thessaly 1370–1373