Doukas, Latinized as Ducas (; feminine: Doukaina/Ducaena, Δούκαινα; plural: Doukai/Ducae, Δοῦκαι), from the Latin tile dux ("leader", "general", Hellenized as [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.