Theodosios Monomachos, Latinized as Theodosius Monomachus (Greek: Θεοδόσιος Μονομάχος), was a senior Byzantine noble and the nephew of Emperor Constantine IX Monomachos. When Constantine's co-ruler, the Empress Theodora died in 1056, Monomachos tried to usurp the throne but failed miserably, was exiled and became a figure of fun in the empire.