Titles of the Pontifical and Imperial Household

15 October 2024; updated 9 September 2025

In the Pontifical Imperial State and the United Roman-Ruthenian Church, the title of Prince-Bishop is sovereign, representing the dual role as both the spiritual and temporal leader of the Church and State. This principal title conveys authority over the ecclesiastical and apostolic realms, extending beyond personal rank. The Prince-Bishop (Roman-Ruthenian Pope) by custom is referred to as Pope, while the consort holds the title of Apostolic Princess. Both hold the style of Apostolic Highness and have additional higher titles that may be formally appended. The most formal style of the Pope is His Apostolic Highness the Most Holy. That may be shortened to His Apostolic Highness, but never merely to Highness. The shortened form is, rather, His Holiness.

In contrast, the title of Grand Duke/Grand Duchess is an honorific held by immediate family members of the Roman-Ruthenian Pope, with the style of Pontifical and Imperial Highness. The title of Grand Duke/Duchess is a noble and dynastic rank and personal distinction within the Pontifical and Imperial Household but does not imply sovereignty. The use of the title 'Prince' by the sovereign pontiff reflects respect for and continuity with ancient traditions: Princeps (Prince), a title originating with Caesar Augustus, and Knyaz, the ancient Slavic term for a sovereign. Thus, while Prince-Bishop signifies supreme, indivisible leadership, the Grand Duke/Grand Duchess title acknowledges high noble status subordinate to the Chief of the Roman-Ruthenian Church and State.

Read more on the Hierarchy of the Household in this article.