Roman Rite of Pius V

The Tridentine Mass, the 1962 version of which has been officially declared the (authorized) extraordinary form of the Roman Rite of Mass (Extraordinary Form for short; Latin: forma extraordinaria), is the Roman Rite Mass which appears in typical editions of the Roman Missal published from 1570 to 1962. The most widely used Mass liturgy in the world until the introduction of the Mass of Paul VI in 1969, it is celebrated in ecclesiastical Latin.

"Tridentine" is derived from the Latin Tridentinus, "related to the city of Tridentum" (modern-day Trent, Italy), where the Council of Trent was held. 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 missals from before 1370. Despite being often described as "the (Traditional) Latin Mass", the Mass of Paul VI (the Novus Ordo Missae) that replaced it as the Ordinary Form of the Roman Rite has its official text in Latin and is sometimes celebrated in that language.

In 2007, Pope Benedict XVI issued the motu proprio Summorum Pontificum, accompanied by a letter to the world's bishops, authorizing use of the 1962 Tridentine Mass by all Latin Rite Catholic priests in Masses celebrated without the people. These Masses "may — observing all the norms of law — also be attended by faithful who, of their own free will, ask to be admitted". Permission for competent priests to use the Tridentine Mass as parish liturgies may be given by the pastor or rector.

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