Roman Missal - Wikipedia

Roman Missal is the book containing all the fixed and changeable prayers and readings for the conduct of Roman Catholic Masses. Before the high Middle Ages priests had to have many books assembled for the Mass - Sacramentaries[?] with the collected prayers; books containing the Gospels, whether arranged in excerpted form organized for public reading or regular Gospel books; and Psalters or collections of the Psalms. The priests of the Franciscan Order who regularly travelled or were posted in preaching assignments all over Europe developed a small-format single volume (or multiple volume set divided by the seasons of the church year) so that they would never be without all the necessary resources.

This practice also advanced the habit of standardization of the Roman Rite by breaking down some local customs; the Franciscans chose the Calendar of Saints as celebrated in the city of Rome rather than adapting their celebrations to the calendar of each diocese in which they operated.

1570, having concluded the revision entrusted to the Pope by the Council of Trent, Pope Pius V published and promulgated a version of the Roman Missal which was to become mandatory for almost all of the Roman Catholic Church belonging to the Latin Rite. This authorative edition suffered some minor changes by later Popes but in it essentials remained unchanged up to the Second Vatican Council.

The Second Vatican Council asked for a revision, to be carried out by the Pope, which was concluded 1969, when Pope Paul VI published and promulgated a new and revised edition of the Roman Missal containing major changes in line with the requirements of the Council. A new edition with minor changes followed 1975 and a third edition 2001, published and aproved by Pope John Paul II.

Like their 1570 predecessor the Roman Missal from 1969 and its later editions have an authorative Latin edition, which can be used for celebrations of the Mass in Latin. But to allow for the celebration of Mass in vernacular languages translations to many languages of the world were prepared by local Bishop Conferences and approved by the Holy See.