John I Doukas of Thessaly

Who was John I Doukas of Thessaly?

John I Doukas, Johannes Doukas or Dukas was ruler of Thessaly from c. 1268 to his death in 1289. By his father's family he is also inaccurately known as John Angelos. He was a descendant of John Doukas son of Constantine Angelos by Theodora Komnene, daughter of the Byzantine Emperor Alexios I Komnenos and Irene Doukaina, hence the combination of family names, "Angelos Komnenos Doukas".

John Doukas was the illegitimate son of Michael II Komnenos Doukas of the Despotate of Epirus by his mistress Gangrene, hence sometimes called John the bastard. He was probably older than his father's other children, and he participated as a military commander in the events that led up to the Battle of Pelagonia in 1259. Married to the daughter of the Thessalian Vlach Taronas, John relied on a force composed largely of Vlachs. John's desertion from the coalition composed by his father, Prince William II Villehardouin of Achaea, and King Manfred of Sicily, contributed to the defeat of the allies by John Palaiologos, the brother of Emperor Michael VIII Palaiologos. Soon afterwards, however, John Doukas repented of his actions and rejoined his father.