 John was a scion of the Armenian Kourkouas family — a Hellenized form of their original surname , Gurgen ( Armenian : <unk> ) — which had risen to prominence in Byzantine service in the 9th century and established itself as one of the great families of the Anatolian land @-@ holding military aristocracy ( the so @-@ called " <unk> " ) . John 's namesake grandfather had been a commander of the elite <unk> regiment ( tagma ) under Emperor Basil I ( reigned 867 – 886 ) ; John 's brother Theophilos became a senior general , as did John 's own son , Romanos , and his great @-@ nephew , John Tzimiskes . 
