Constantine X Doukas

Constantine X Doukas or Dukas, Latinized as Ducas (Greek: Κωνσταντῖνος Ι΄ Δούκας, Kōnstantinos X Doukas) (1006 – 22 May 1067) was emperor of the Byzantine Empire from 24 November 1059 to 22 May 1067.

Constantine Doukas was the son of Andronikos Doukas, a Paphlagonian nobleman who may have served as governor of the theme of Moesia. Addicted to endless debates about philosophy and theology, Constantine gained influence after he married, as his second wife, Eudokia Makrembolitissa, a niece of Patriarch Michael Keroularios. In 1057, Constantine supported the usurpation of Isaac I Komnenos, gradually siding with the court bureaucracy against the new emperor's reforms. In spite of this tacit opposition, Constantine was chosen as successor by the ailing Isaac in November 1059, under the influence of Michael Psellos. Isaac abdicated, and on November 24, 1059, Constantine X Doukas was crowned emperor.

The new emperor quickly associated two of his young sons in power, Michael VII Doukas and Konstantios Doukas, appointed his brother John Doukas as kaisar (Caesar), and embarked on a policy favorable to the interests of the court bureaucracy and the church. Severely undercutting the training and financial support for the armed forces, Constantine X fatally weakened Byzantine defences by disbanding the Armenian local militia of 50,000 men at a crucial point of time, coinciding with the westward advance of the Seljuk Turks and their Turcoman allies. Undoing many of the necessary reforms of Isaac I, he bloated the military bureaucracy with highly paid court officials and crowded the Senate with his supporters.

His decisions to replace standing soldiers with mercenaries and leaving the frontier fortifications unrepaired led Constantine to become naturally unpopular with the supporters of Isaac within the military aristocracy, who attempted to assassinate him in 1061. He also became unpopular with the general population after he raised taxes to try to pay the army.

Constantine lost most of Byzantine Italy to the Normans under Robert Guiscard, except for the territory around Bari, though a resurgence of interest in retaining Apulia occurred under his reign, and he appointed at least four catepans of Italy: Miriarch, Maruli, Sirianus, and Mabrica. He also suffered invasions by Alp Arslan in Asia Minor in 1064, resulting in the loss of the Armenian capital, and by the Oghuz Turks in the Balkans in 1065, while Belgrade was lost to the Hungarians.

Already old and unhealthy when he came to power, Constantine died on May 22, 1067. His final act was to demand that only his sons succeed him, forcing his wife Eudokia Makrembolitissa to take a vow not to remarry.

By his first wife, a daughter of Constantine Dalassenos, Constantine X Doukas had no known children. By his second wife, Eudokia Makrembolitissa, he had the following issue:

• Michael VII Doukas, who succeeded as emperor.
• Andronikos Doukas, co-emperor from 1068 to 1078.
• Konstantios Doukas, co-emperor from c. 1060 to 1078, died 1081.
• Anna Doukaina, a nun
• Theodora Anna Doukaina, who married Domenico Selvo, Doge of Venice.
• Zoe Doukaina, who married Adrianos Komnenos, a brother of Emperor Alexios I Komnenos.