John's early life is unknown, and he first appears in November 1162 in a document concerning a property dispute of the
Great Lavra monastery. At the time he served as
doux (governor) of
Thessalonica, with the parallel roles of
apographeus and
exisotes (tax assessor). He is then mentioned among the attendants of a
synod at the
Blachernae Palace in March 1166, along with his brother Alexios. John also appears to have taken part in his uncle Manuel I's campaigns, but with the exception of the campaign of 1176 against the
Seljuk Sultanate of Rum, this is not explicitly attested. Even in the latter, he is only mentioned in the summer of 1176, when his brother Alexios died of an illness at
Lopadion. It is hence unclear if he participated in the
Battle of Myriokephalon on 17 September. As he is not mentioned thereafter, it is possible that he was one of the many members of the aristocracy who perished in the battle. According to Konstantinos Varzos, John was most likely dead by 1182, when his brother Andronikos rebelled against the usurper
Andronikos I Komnenos. ==References==