Constantine played a pivotal role in placing his son on the throne by engineering the murder of Philip, the husband of Isabella, Queen of Armenia.
He tricked Philip's father, Bohemond IV of Antioch, to search for his son at Amouda rather than at Sis, where he was being tortured and poisoned.
He then took his army to the gates of Silifke Castle, forced its Frankish lords to surrender Isabella, and arranged the marriage, making his son the first Het‛umid ruler of the Armenian Kingdom.
[1] Nearby, at a site known today as Kız Kilisesi near Gösne, he built a monastic retreat with an ornate chapel whose dedicatory inscription is dated to 1241.
[2][3][4] The Castle of Tamrut, about 75 km northeast of Baberon, also had an Armenian dedicatory inscription (now destroyed) over its main gate which mentioned having been built in memory of “the father of the King… Baron Constantine.” It also gave the medieval Armenian name of the castle as Tambrout, a name otherwise unattested in the surviving histories, and the year of construction as 1253.