The Missal of St. Pius V was compiled and published in obedience to the Fathers of the Council of Trent. Their intentions were well expressed by Fr. Fortescue:

The Protestant Reformers naturally played havoc with the old liturgy. It was throughout the expression of the very ideas (the Real Presence, Eucharistic Sacrifice, and so on) they rejected. So they substituted for it new communion services that expressed their principles but, of course, broke away utterly from all historic liturgical evolution. The Council of Trent ( 1545­ 1563), in opposition to the anarchy of these new services, wished the Roman Mass to be celebrated uniformly everywhere. The medieval local uses had lasted long enough. They had become very florid and exuberant; and their variety caused confusion!

The first priority of the Council of Trent was to codify Catholic Eucharistic teaching. It did this in very great detail and in clear and inspiring terms. Anathema was pronounced upon anyone who rejected this teaching, and the Fathers insisted that what they had taught concerning the Eucharist must remain unmodified until the end of time:

And so this Council teaches the true and genuine doctrine about this venerable and divine sacrament of the Eucharist, the doctrine which the Catholic Church has always held and which She will hold until the end of the world, as She learned it from Christ Our Lord Himself, from His Apostles, and from the Holy Ghost, Who continually brings all truth to Her mind The Council forbids all the faithful of Christ henceforth to believe, teach or preach anything about the most Holy Eucharist that is different from what is explained and defined in the present decree.

In its eighteenth session, the Council appointed a commission to examine the Missal, to revise and restore it "according to the custom and rite of the Holy Fathers." Doctor Fortescue considers that the members of the Commission established to revise the Missal "accomplished their task very well":

It was not to make a new Missal, but to restore the existing one "according to the custom and rite of the holy Fathers," using for that purpose the best manuscripts and other documents.

He makes particular mention of the liturgical continuity which characterized the new Missal. The Missal promulgated by St. Pius V is not simply a personal decree of the Sovereign Pontiff, but an act of the Council of Trent, even though the Council closed on 4 December 1563, before the commission had completed its task. The matter was remitted to Pope Pius IV, but he died before the work was concluded so that it was his successor, St. Pius V, who promulgated the Missal resulting from the Council, with the Bull Quo Primum Tempore, 14 July 1570. Because the Missal is an act of the Council of Trent, its official title is Missale Romanum ex decreto sacrosancti Concilii Tridentini restitutum ("The Roman Missal Restored According to the Decrees of the Holy Council of Trent"). This was the first time during the one thousand five hundred and seventy years of the Church's history that a council or pope had used legislation to specify and impose a complete rite of Mass.