Stephen was born in c. 1107, the son of the sebastos Isaac Kontostephanos,[1] a military commander for most of the reign of Alexios I Komnenos (r. 1081–1118), culminating in his unsuccessful service as admiral (thalassokrator) against the Italo-Normans in 1107/8.
[4] In c. 1126, he married Anna, the second-born daughter of Emperor John II Komnenos (r. 1118–1143) and Irene of Hungary, and received the title panhypersebastos.
[1] The couple had four children: the sons John, Alexios, and Andronikos, as well as a daughter, Irene, who married Nikephoros Bryennios.
When Cosmas, enraged at his dismissal, cursed the empress never to bear a male child, Stephen, a nervous and impetuous man, according to Niketas Choniates, tried to attack the patriarch, but at the last moment reined himself in.
This made a bad impression among all the attendants, but Cosmas reportedly prophesied that Stephen would soon receive his due blow as punishment.