John Doukas

John Doukas (or Ducas) (, Iōannēs Doukas) (died ) was the son of Andronikos Doukas, a Paphlagonian Greek nobleman who may have served as governor of the theme of Bulgaria (Moesia), and the younger brother of Emperor Constantine X Doukas. John Doukas was the paternal grandfather of Irene Doukaina, wife of Emperor Alexios I Komnenos. He is the scribe of Codex Parisinus graecus 2009, i.e. the oldest known and preserved manuscript of De administrando imperio of Emperor Constantine VII Porphyrogenitus, a well-known encyclopedic Byzantine source on foreign nations from the 10th century. Career as Caesar John Doukas, who was given the court dignity of Caesar by his brother Constantine X, was one of the most influential members of the court aristocracy from the death of his brother into that of Alexios I Komnenos. His wealth derived of estates in Thrace and Bithynia, and he was a close friend of the historian Michael Psellos. Although he is usually documented by the sources as a member of the court, he had begun his career as a general.