Ducas

Doukas, Latinized as Ducas (Greek: Δούκας; feminine: Doukaina/Ducaena, Δούκαινα; plural: Doukai/Ducae, Δοῦκαι), from the Latin tile dux ("leader", "general", Hellenized as δοὺξ [ðoux]), is the name of a Byzantine Greek noble family, whose branches provided several notable generals and rulers to the Byzantine Empire in the 9th–11th centuries. A maternally-descended line, the Komnenodoukai, founded the Despotate of Epirus in the 13th century, with another branch ruling over Thessaly. After the 12th century, the name "Doukas" and other variants proliferated across the Byzantine world, and were sometimes presented as signifying a direct genealogical relationship with the original family or the later branch based in the Despotate of Epirus.

The continuity of descent amongst the various branches of the original, middle Byzantine family is not clear, and historians generally recognize several distinct groups of Doukai based on their occurrence in the contemporary sources. According to Demetrios I. Polemis, who compiled the only overview work on the bearers of the Doukas name, in view of this lack of genealogical continuity "it would be a mistake to view the groups of people designated by the cognomen of Doukas as forming one large family".

Nothing is known for certain about the family's origin. Later tradition, mentioned by the historian Nikephoros Bryennios, held that they descended from a cousin of the Roman emperor Constantine I who had migrated to Constantinople in the 4th century and allegedly became the city's governor with the title of doux. This tradition is, however, evidently an invention meant to glorify the family, at the time the Empire's ruling dynasty, by 11th-century court chroniclers. In fact, it is more likely that the surname derives from the relatively common military rank of doux. Nothing is known about the family's origin. Several authors have raised the possibility of an Armenian descent, but it is almost certain that the Doukai were in fact native-born Greek-speakers, probably from Paphlagonia in north-central Anatolia, where their estates were located.

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