Isaac Komnenos or Comnenus, was the third son of Byzantine Emperor John II Komnenos by Irene of Hungary. He was bypassed by his father in favour of his younger brother Manuel I Komnenos for the succession, leading to a tense relationship between the two brothers after. He participated in the campaigns of his father and brother in Asia Minor, and was a fervent adherent of Patriarch Cosmas II of Constantinople, but little else is known about his life.

John II Komnenos or Comnenus was Byzantine emperor from 1118 to 1143. Also known as "John the Beautiful" or "John the Good", he was the eldest son of Emperor Alexios I Komnenos and Irene Doukaina and the second emperor to rule during the Komnenian restoration of the Byzantine Empire. As he was born to a reigning emperor, he had the status of a porphyrogennetos. John was a pious and dedicated monarch who was determined to undo the damage his empire had suffered following the Battle of Manzikert, half a century earlier.