Konstantios Doukas, Byzantine Co-Emperor

-https://en.wikipedia.org/wiki/Konstantios_Doukas

-https://fmg.ac/Projects/MedLands/BYZANTIUM%2010571204.htm#Konstanti...

KONSTANTIOS Doukas (1060-killed in battle Durazzo 18 Oct 1081). Mikhael Glykas names "Michaelum, Andronicum et Constantinum purpurigenam" as the sons of Emperor Konstantinos & his wife[657]. Nikeforos Bryennios names "eius coniuge Eudocia, cum Michaele, Andronico et Constantino filiis" as survivors of "Ducas"[658]. Psellos records that "the sun had not yet completed its yearly cycle after Constantine's promotion when another child was born"[659]. Psellos names "Constantine…a child" as one of the two sons with his mother after their father died, commenting that his older brother Mikhael "used to sit on the imperial throne beside his brother Constantine"[660]. Co-emperor 1067-1078. He was confined to a monastery after his brother's abdication by the latter's successor Emperor Nikeforos Botaneiates[661]. The Alexeiad records the death of "Constantius the son of the former emperor Konstantinos Doukas…born…in the Porphyra" while fighting Robert "Guiscard" Duke of Apulia in Durazzo in 1081[662].