[1][2] Constantine was crowned co-emperor by his father shortly after his birth, and was betrothed to Olympias, the daughter of Robert Guiscard, the Norman duke of Apulia.

This arrangement was cancelled after Michael abdicated in 1078, whereupon Maria and Constantine retired to the Monastery of Petrion.

[8] In order to combat this invasion, Alexios I Komnenos was given a large force to repel the Norman army led by Guiscard.

[10] After Alexios ascended the throne in 1081, he elevated Constantine to junior emperor,[11] and betrothed his daughter Anna Komnene to him in 1083, shortly after her birth.

[13] Constantine Doukas is thought to be engraved on the Holy Crown of Hungary, which was given to Hungarian King Géza I of Hungary by Constantine's father Michael VII, depicted alongside King Geza I and Michael VII;[14] although the figure may actually be Konstantios Doukas.