History of Catholicism in Italy
- A collection of open source Wikipedia articles on the history of the Catholic Church in Italy.
- http://en.wikipedia.org/wiki/Category:History_of_Catholicism_in_Italy

Christianity's First Cathedral
- A history and tour of the earliest Christian basilica and home of the Popes, St. John Lateran.
- http://www.catholicculture.org/docs/doc_view.cfm?recnum=5811

Christian martyrs of Rome
- A short set of articles about the early Christian martyrs in Rome.
- http://www.cptryon.org/compassion/sum00/martyrs.html

Catacombs: Witness To Early Heroism
- The Pope's Message to the Pontifical Commission for Sacred Archaeology.
- http://www.catholicculture.org/docs/doc_view.cfm?recnum=4204