“The Braga liturgy” is an excerpt from a doctoral dissertation made up of a study and edition of MS. 870 of the Braga District Archive, defended in June 2007 at the Saint Anselm Pontifical Liturgical Institute, Rome. The a quo and ao quem limits of this de luxe Braga-Roman pontifical have been fixed at 1485-1516. Assembled for the Archbishop of Braga, this codex was used by him when he came to the cathedral to celebrate the principal solemnities of the liturgical year. The present text corresponds to the first part of Chapter II, dedicated to a historical study, both diachronic and synchronic. The results of its application indicate that the history of the liturgy of this particular Church is complex, and that the factors incolved in its evolution are primarily external. The inorganic discountinuities introduced in printed books throughout the 16th century, largely ignored up to the present, provide ample proof of this and enable us to modify our knowledge of this local liturgy.