Francis slammed the spread of the old Latin Mass on Friday, reversing one of Pope Benedict XVI’s signature decisions in a major challenge to traditionalist Catholics, who immediately denounced it as an attack on them and the ancient liturgy.

Francis reinstated the restrictions on celebrating the Latin Mass that Benedict had lifted in 2007, and went even further to limit its use. The pontiff stated that he was acting because Benedict’s reform had caused division in the church and had been used by Catholics opposed to the Second Vatican Council, the 1960s meetings that modernized the church and its liturgy.

Critics claimed that they had never seen a pope so completely reverse his predecessor. The fact that the reversal concerned something as fundamental as the liturgy, while Benedict is still alive and well and living in the Vatican as a retired pope, only added to the extraordinary nature of Francis’ move, which will almost certainly result in more right-wing hostility directed at him.

Francis, 84, issued a new law requiring individual bishops to approve celebrations of the old Mass, also known as the Tridentine Mass, and newly ordained priests to obtain explicit permission to do so from their bishops, in consultation with the Vatican.

Bishops must also determine whether the current groups of faithful associated with the old Mass accept Vatican II, which allowed Mass to be celebrated in vernacular rather than Latin. These groups cannot worship in regular churches; instead, bishops must find alternative locations for them without establishing new parishes.

Furthermore, Francis stated that bishops are no longer permitted to authorize the formation of new pro-Latin Mass groups in their dioceses.

Francis stated that he was taking steps to promote unity and heal divisions within the church that had grown since Benedict’s Summorum Pontificum document in 2007. He stated that his decision was based on a 2020 Vatican survey of all the world’s bishops, the results of which “reveal a situation that preoccupies and saddens me, and persuades me of the need to intervene.”

The pope’s reversal sparked outrage among traditionalists who were already opposed to Francis’ more progressive stance and nostalgic for Benedict’s doctrinal papacy.

Benedict issued his document in 2007 to reach out to the Society of St. Pius X, a schismatic group that celebrates the Latin Mass and had split from Rome over Vatican II’s modernizing reforms. However, Francis stated that Benedict’s efforts to foster unity had largely failed.

The pope said in a letter to bishops accompanying the new law that Benedict’s opportunity was instead “exploited to widen the gaps, reinforce the divergences, and encourage disagreements that injure the Church, block her path, and expose her to the peril of division.”

Francis, according to Christopher Bellitto, a professor of church history at Kean University, was correct to intervene, noting that Benedict’s original decision had a slew of unintended consequences that not only created internal divisions but also temporarily strained relations with Jews. The backlash was fierce, but it’s also possible that many will simply ignore Francis’ decree and continue on with sympathetic bishops as before. Some of these traditionalists and Catholics were already among Francis’ harshest critics, with some accusing him of heresy for allowing divorced and civilly remarried Catholics to receive Communion.

For years, Francis has made clear his disdain for the old liturgy, privately labeling its adherents as self-referential navel-gazers who are disconnected from the needs of the church. He has cracked down on religious orders that only celebrated the old Mass and has frequently decried the “rigidity” of rule-following priests who prioritize rules over pastoral accompaniment.

Traditionalists have maintained that the old liturgy was never abolished and that Benedict’s 2007 reform allowed it to thrive.

They point to the expansion of traditionalist parishes, which are frequently frequented by young, large families, as well as new religious orders that celebrate the old liturgy. According to the Latin Mass Society, the number of traditional Masses held each Sunday in England and Wales has more than doubled since 2007, rising from 20 to 46.

But the writing was on the wall for many when Francis stepped out onto the loggia of St. Peter’s Basilica after his 2013 election without the ermine-trimmed red velvet cape that Benedict preferred and is a symbol of the pre-Vatican II church.

The restrictions went into effect immediately after they were published in the official Vatican newspaper, L’Osservatore Romano, on Friday.