"The Tridentine Mass means the rite of the Mass which was fixed by Pope Pius V at the request of the Council of Trent and promulgated on December 5, 1570. This Missal contains the old Roman rite, from which various additions and alterations were removed. When it was promulgated, other rites were retained that had existed for at least 200 years. Therefore, is more correct to call this Missal the liturgy of Pope Pius V."