Before 1108: Strategos in the service of emperor Alexios I Komnenos (1081-1118) having the title of protosebastos"
1108: Constantine Gabras goes to the city of Petroula in order to intercept the Normans
1112: Victory of Gabras and the Byzantines against the Seljuk Turks at the battle of Kelvianon, not far from Philadelpheia
1113: Battle of Akrokou with the participation of Gabras under the command of emperor Alexios I Komnenos
1116: In charge of the left wing during the campaign of the Byzantine Emperor in Asia Minor. He participates in a battle near Philomelion
Before 1119 and until 1140: Doux of Trebizond (Chaldia)
1119: Gabras is captured by the Danişmendids
1126: Gabras returns to Trebizond
1130: Gabras offers refuge to Isaac Komnenos
1139-1140: Unsuccessful campaign of the Byzantine emperor John II Komnenos in order to recapture Tzanicha and Chaldia
Middle of the 1160s: Chaldia is annexed again to the Byzantine administration