Ad Altare Dei.org is the online home for The Gregorian Society of Baltimore. The society was founded to preserve and foster the Traditional Latin Mass, Traditional sacraments and ceremonies of the Roman Rite within the Catholic Archdiocese of Baltimore. The Society is loyal to the Magisterium of the Roman Catholic Church and functions with the approval of the Baltimore Archdiocese.

The Gregorian Society was founded in Baltimore in the 1990s so the Society members could formulate a Latin Mass community. Our founding goal was to build a community centered around the Traditional Latin Mass. This community formulated at St. Alphonsus in Baltimore, MD (now the National Shrine of Saint Alphonsus). Since the arrival of the Priestly Fraternity of Saint Peter (FSSP) the community and Gregorian Society is more committed to supporting the Traditional Latin Mass and the FSSP priests who serve our community.