Doukas

The House of Doukas (pl. Doukai; , pl. , feminine form Doukaina; ), Latinized as Ducas, was 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.

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. 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".