The Tridentine Mass
The Tridentine Mass, often referred to today as the Forma Extraordinaria (extraordinary form) or the Latin Mass, is the form of the Mass found in the Roman Missal published from 1570 to 1962. The term Tridentine comes from the Latin word Tridentinus which means “related to the city of Tridentum(modern day Trent, Italy)”. The Council of Trent in the 1500s called for the Roman Missal to standardize the liturgy of the Mass for the Roman Rite of the Church. In 1570, Pope Pius V made the Roman Missal mandatory throughout the Western Church, codifying the Latin liturgy of the Mass for the next 400 years.
In 1962 the ordinary form of the Mass was changed by Pope Paul VI in response the Vatican II’s call for the Mass to be allowed in the vernacular, thus resulting in the prior Mass or Tridentine Mass being labeled the extraordinary form. Both Pope John Paul II and Pope Benedict have allowed for the celebration of the Latin Mass on a regular basis.
If you wish to learn about the Tridentine Mass we would refer you to an excellent website Sancta Missa.