Ruben I, Prince of Armenia

Ruben I, (; 1025–1095) was the first lord of Armenian Cilicia from 1080 until his death.

The first movement of Armenian nobles immigrating to the Byzantine Empire began during the reign of Emperor Maurice, when Armenians voluntarily joined the Byzantine army. Gagik was later assassinated by the Byzantine governors of Kyzistra. After Gagik II was killed, his relatives and followers fled to the Taurus Mountains and found refuge in the castle of Kapitar, north of Kozan.

In 1079 Ruben's troops advanced south to Kozan and captured the city from the Empire. Through continuous military campaigns against the Byzantines, he managed to expand his territory to the entire plain of Cilicia, in one of which he captured the powerful Castle of Antirim and made it a military base for his family. His descendants are called Rubenids.

Death He was 70 when he died, buried at the monastery of Castalon.

Marriage and children The name of Roupen’s wife is unknown. His recorded children are: Constantine I of Cilicia (1035/1055 – 24 February 1102 / 23 February 1103) (?) Thoros of Marash (according to Rüdt-Collenberg, he was the brother of Constantine I)