Person
John Doukas
Usurper of the East Roman (Byzantine) empire
John Doukas (or Ducas) (died c. 1088) is the son of Andronikos Doukas, a Paphlagonian nobleman who may have served as governor of the theme of Moesia and younger brother of Emperor Constantine X Doukas.
John Doukas is the paternal grandfather of Irene Doukaina, wife of Emperor Alexios I Komnenos.