In the age of forty, patriarch Gregory Petros XV, had thought previously in Rome, philosophy and theology at the university of Propaganda.

Towards his capacities to accomplish some missions which needed confidence, Rome thought to use him far from the Armenian Catholic community. In 1946, he was designated cardinal (the second after Antoine IX). Managing the positions of patriarch and cardinal between Lebanon and Rome, the Holy Seat called him to come to the Vatican. Because of the holiness of his life , the kindness of his character , the people of Rome were guessing that he was elected Pope during the secret meeting of priest election of 1963, but he refused it.
The church of Lebanon and its politics will remind his services towards this country.