Skip to main content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Church History (Patristic Era, Ecumenical Councils, the Papacy, and Saints): Papacy

The historical development of the Church...Within 400 years after Jesus' passion, Christianity developed from an illegal, persecuted, and underground religion into the sole, official, dominant faith of the Roman Empire.

Finding Information on Popes

The items on this page can provide basic biographical and historical information about popes and the Papacy.  For documents or books written by a particular Pope, please consult the CLICsearch. Most works are listed under Papal names. For example, works by Joseph Ratzinger will be attributed to Benedict XVI, Pope, even if they were written before he became Pope.

History of the Papacy

Papal Documents


For Papal documents, try the Vatican Website and sets of monographs listed below. For more recent encyclicals in paper format, search CLICsearch.  For texts and commentary on recent ones, try the Vatican Web site and use our online theological databases.  For older articles try using the historic Catholic Periodical and Literature Index (CPLI) in Ireland Library's Reference Room  to locate articles in the Osservatore Romano, Origins, or other Catholic publications.


Pope and Saint


Pope Saint Gregory the Great.

(76 Popes have been canonized as saints.)

Acta Apostolicae Sedis

Acta Apostolicae Sedis is the official, polyglot chronological commentary on the actions of the popes.