Early Medieval Mass

Pre-Tridentine Mass refers to the variants of the liturgical rite of Mass in Rome before 1570, when, with his bull Quo primum, Pope Pius V made the Roman Missal, as revised by him, obligatory throughout the Latin-Rite or Western Church, except for those places and congregations whose distinct rites could demonstrate an antiquity of two hundred years or more.

The Pope made this revision of the Roman Missal, which included the introduction of the Prayers at the Foot of the Altar and the addition of all that in his Missal follows the Ite missa est, at the request of Council of Trent (1545–63), presented to his predecessor at its final session.

Outside Rome before 1570, many other liturgical rites were in use, not only in the East, but also in the West. Some Western rites, such as the Mozarabic Rite, were unrelated to the Roman Rite which Pope Pius V revised and ordered to be adopted generally, and even areas that had accepted the Roman rite had introduced changes and additions. As a result, every ecclesiastical province and almost every diocese had its local use, such as the Use of Sarum, the Use of York and the Use of Hereford in England. In France there were strong traces of the Gallican Rite. With the exception of the relatively few places where no form of the Roman Rite had ever been adopted, the Canon of the Mass remained generally uniform, but the prayers in the "Ordo Missae", and still more the "Proprium Sanctorum" and the "Proprium de Tempore", varied widely.

The earliest surviving account of the celebration of the Eucharist or the Mass in Rome is that of Saint Justin Martyr (died c. 165), in chapter 67 of his First Apology:

...
Wikipedia