Tridentine Mass

The Tridentine Mass, also known as the Extraordinary Form of the Roman Rite, the usus antiquior (Latin for 'more ancient use'), the Vetus Ordo ('Old Order'), the Traditional Latin Mass (TLM), or the Traditional Rite, is the form of Mass found in the Roman Missal of the Catholic Church codified in 1570 and published thereafter with amendments up to 1962. Celebrated almost exclusively in Ecclesiastical Latin, it was the most widely used Eucharistic liturgy in the world from its issuance in 1570 until its replacement by the Mass of Paul VI promulgated in 1969 (with the revised Roman Missal appearing in 1970).

"Tridentine" is derived from the Latin Tridentinus, lit. 'relating to the city of Trent', where the Council of Trent was held at the height of the Counter-Reformation. In response to a decision of that council, Pope Pius V promulgated the 1570 Roman Missal, making it mandatory throughout the Latin Church, except in places and religious orders with rites or uses from before 1370.

Permissions for celebrating the Tridentine Mass have been adjusted by successive popes, and most recently restricted by Pope Francis's motu proprio Traditionis custodes in 2021. This has been controversial among traditionalist Catholics.

Terminology

The term "Tridentine Mass" applies to celebrations in accordance with the successive editions of the Roman Missal whose title attribute them to the Council of Trent (Missale Romanum ex decreto Sacrosancti Concilii Tridentini restitutum) and to the pope or popes who made the revision represented in the edition in question. The first of these editions is that of 1570, in which the mention of the Council of Trent is followed by a reference to Pope Pius V (Pii V Pont. Max. iussu editum).