Commemoration (liturgy)

In the Latin liturgical rites, a commemoration is the recital, within the Liturgy of the Hours or the Mass of one celebration, of part of another celebration, generally of lower rank, that is impeded because of a coincidence of date.

The parts commemorated are readings, antiphons and prayers.

In the Liturgy of the Hours, all three are or have been used: a reading of the commemorated celebration at Matins (Office of Readings); the antiphons of the Benedictus at Lauds and of the Magnificat at Vespers; and the proper prayer of the celebration being commemorated, the same as the collect of its Mass.

At Mass, the prayers used are the collect, the prayer over the offerings and the prayer after Communion.

Furthermore, before the 1955 decree Cum nostra hac aetate, in the Liturgy of the Hours the verse in the short responsory at Prime and the doxology in hymns of a commemorated feast that had special ("proper") forms of these were used, as at Mass were the commemorated feast's preface, if "proper", and the Credo, if the commemorated feast required its recitation.

Originally there were no commemorations at Mass. The older sacramentaries have only one collect. Even when, in the ninth century, priests began elsewhere to say more than one collect, only one was used in Rome. However, even in Rome the number of collects gradually increased.

Pope Pius V promulgated official editions of the Roman Breviary (in 1568) and the Roman Missal (in 1570) at the request of the Council of Trent. These admitted several commemorations on the same day. Thus, on 29 December the liturgy celebrated was that of Saint Thomas Becket with commemorations of the Octaves of Christmas, Saint Stephen, John the Apostle and the Holy Innocents. (See Tridentine Calendar.)

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