The Tridentine Mass (also known as Old Latin Mass) is an old form of Mass of the Catholic Church that came into being in 1570. It was replaced in the 1960s after the second Vatican Council. It is held exclusively in Ecclesiastical Latin.
Recently, Pope Francis restricted the use of the old Latin Mass, reversing the decision of his predecessor Pope Benedict XVI, who relaxed restrictions on the Mass. the new law requires priests to get permission from their bishop and in some cases, bishops will be have to consult with the Vatican before granting approval.