Pope St. Pius V (17 January 1504 – 1 May 1572), born Antonio Ghislieri (from 1518 called Michele Ghislieri, O.P.), was pope from 1566 to 1572 and is a saint of the Roman Catholic Church. He is chiefly notable for his role in the Council of Trent, the Counter-Reformation, and the standardisation of the liturgy.
Before Michele Ghislieri could return to his episcopate, Pope Pius IV died. On 7 January, 1566, Ghislieri was elected to the Papal chair as Pope Pius V. He was crowned ten days later, on his 62nd birthday. The prudence of Giovanni Francesco Commendone saved him at the commencement of his pontificate from trouble[clarification needed] with Germany, as in the general diet of the empire at Augsburg, 26 March, 1566.
Aware to the necessity of restoring discipline and morality at Rome to ensure success without, he at once proceeded to reduce the cost of the papal court after the manner of the Dominican Order to which he belonged, compel residence among the clergy, regulate inns, expel prostitutes, and assert the importance of the ceremonial in general and the liturgy of the Mass in particular. In his wider policy, which was characterised throughout by an effective stringency, the maintenance and increase of the efficacy of the Inquisition and the enforcement of the canons and decrees of the Council of Trent had precedence over other considerations.:)
Accordingly, in order to implement a decision of that council, he standardised the Holy Mass by promulgating the 1570 edition of the Roman Missal. Pope Pius V made this Missal mandatory throughout the Latin rite of the Catholic Church, except where a Mass liturgy dating from before 1370 was in use. This form of the Mass remained essentially unchanged for 400 years until Pope Paul VI's revision of the Roman Missal in 1969-70, after which it has become widely known as the Tridentine Mass; use of the last pre-1969 edition of the Missal, that by Pope John XXIII in 1962, is permitted without limitati...