Roman Missal

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 - Sacrametaries? 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.