This research is aiming to focus on the challenge of power between France and the Holy See in front of the Sublime Porte for representing and protecting the Catholic Subjects in the 19th and 20th centuries the establishment and development of the French Protectorate in the Ottoman lands its abolishment and the diplomatic attempts of the Apostolic Delegates for being recognized by the Ottoman &Turkish authorities as the representative of the Pope until the reciprocal appointment of ambassadors in 1960