In 2007, Benedict himself issued a Motu Proprio increasing access to the celebration of the traditional Latin Mass, a move seen as a microcosm of the church’s shift toward traditionalism during his papacy.

In changing the law, which will go into effect on Oct. 1, the pope recalled that the Vatican Council entrusted bishops with the “weighty task of introducing the vernacular language into the liturgy.” He added that “in order that the renewal of the whole liturgical life might continue, it seemed opportune that some principles handed on since the time of the council should be more clearly reaffirmed and put into practice.”

He also acknowledged the bitter feelings that the fights over liturgical language have produced, writing, “It is no surprise that difficulties have arisen” between local churches and the Vatican. He then called for “reciprocal trust” between the local churches and the Vatican department with liturgical oversight, known as the Congregation for Divine Worship and the Discipline of the Sacraments.

But Vatican observers say trust is in short supply between the pope and the cardinal he selected in 2014 to run the department, Robert Sarah.

A hero to Vatican conservatives — and for many, a desired candidate in the next conclave to choose a new pope — Cardinal Sarah has been undermined by partisans of Francis who have worked on a committee to loosen the Guinean cardinal’s cherished Latin literalism.

In 2016, Cardinal Sarah called for priests to celebrate Mass ad orientem, or with their backs to the congregation. Francis promptly issued an unusual public rebuke. And in April of this year, Cardinal Sarah sent a letter honoring Benedict’s support of the Latin Mass, asserting that “modern liturgy” had caused devastation and schism. Benedict wrote that “the liturgy is in good hands,” in an afterward to a book the cardinal wrote this year.

But the liturgy seems to have been in the hands of Francis all along.

Saturday’s Vatican announcement was made as the pope visited Medellin, Colombia, the site of a landmark 1968 meeting that emphasized local Latin American influence in church decision-making. It also came just weeks after the pope — not one to invoke his magisterial authority — did just that when he announced that the liturgical reform of the Second Vatican Council was “irreversible.”