Tags: Monarch.
Konstantios Doukas (Greek: Κωνστάντιος Δούκας 1060–1082) Latinized as Constantius Ducas was the son of Byzantine Emperor Constantine X Doukas and younger brother of Byzantine Emperor Michael VII Doukas. He reigned as junior co-emperor from his birth but was unable to establish himself as sole emperor against Nikephoros III when Michael VII abdicated in 1078.