Motu Proprio Summorum Pontificum, issued by His Holiness Pope Benedict XVI.
Until Summorum Pontificum was issued it was believed, and taught by many, that the Roman Rite, as it was when the last edition of the Roman Missal was issued in 1962, has been abolished and replaced by a New Roman Rite, the Novus Ordo. Thus in order for priests to celebrate the Mass according to the 1962 Missal they had to obtain an indult (permission from their bishop and the Holy See). Benedict XVI declared that, juridically, there is no Old Roman Rite and New Roman Rite, but a single Roman Rite with two liturgical forms or uses. By saying this he contradicted the previous belief (something completely within his authority to do) and said that any priest of the Roman Rite is allowed to celebrate Mass in the older form without need for any indult or special permission.
