Pope Francis began a three-nation Africa tour last week, and for good reason. Africa has the fastest-growing Catholic population on the planet, which is projected to reach nearly 350 million by 2050.

As Francis reaches out to this growing population of the faithful, he would do well to look to the history of Catholicism in the region. He should do so not just to connect Catholic Africans to their past, but to underscore his own message of change. As a reformer who seeks to shake up the church, Francis can draw inspiration from Africans who played a key role in the reorientation of Catholicism in the 1950s and 1960s.

Francis’s visit comes at a moment when Catholicism is in the midst of a titanic shift, comparable in historical importance to its early spread in the Roman Empire or to the upheavals of the Protestant Reformation. The church’s strength in its longtime strongholds in Europe is evaporating. Priestly vocations are so rare there that bishops increasingly rely on clergy from Africa to lead their churches. In 2015, for example, there were over 1,000 francophone African priests working in France.

The church’s growth in Africa is part of its stunning success in the global south, which the election of Francis, the first Latin American pope, reflects.

What is equally remarkable is that the Catholic transformation in Africa has come about in the space of only two generations. Consider the fact that there were no modern African saints in the church until 1964, when Paul VI canonized the Ugandan martyrs during the Second Vatican Council. Moreover, no sitting pope had set foot in sub-Saharan Africa until 50 years ago, when Paul went to Uganda to visit the new saints’ shrine in the summer of 1969.

At that time, though much of Africa had become independent from European control, the church still relied heavily on missionaries from the former colonial powers to tend its African flocks. African prelates occupied the most visible episcopal seats beginning in the late 1950s, but there were not enough of them, nor enough African priests, to go around. Yet today, these same missionary societies are increasingly African in composition. The venerable Society of Missionaries of Africa, founded by the French Cardinal Charles Lavigerie and known colloquially as the “White Fathers,” is currently headed by a Zambian, Father Stanley Lubungo.

How did this transition happen so quickly? And why did it take place in the second half of the 20th century? After all, European Catholic missionaries had been evangelizing Africa for decades, sometimes centuries, before that. Why did a process that had proceeded incrementally for a long time suddenly accelerate exponentially?

The era of decolonization between 1945 and 1965 was the crucial turning point. After World War II, even as European powers were trying desperately to hold on to their African colonies, the Vatican began distancing itself from colonial regimes and exhorting European missionaries to train their own African replacements as quickly as possible.

At first, the Vatican thought almost exclusively in terms of having enough local clergy on the ground to man the pulpits should Europeans be expelled from a given territory. But “decolonizing” the church came to mean much more than that, thanks to African Catholic intellectuals, clergy and laity who called on the hierarchy to make Catholicism more hospitable to Africans. For them, this meant holding Catholicism to its fundamental claim to be universal, and not merely European. It had to be able to embrace African culture, African values and African people.

The most prominent among these activist African Catholics was Alioune Diop, a Senegalese convert from Islam who was the behind-the-scenes organizer of the negritude movement. Negritude, which first emerged among African and Afro-Caribbean francophone writers in mid-20th-century Paris, celebrated black literature, art and culture, while rejecting colonialism and assimilation to European norms.

Diop founded the bilingual journal Présence Africaine, which published the work of black writers, thinkers and artists, and a publishing house and a bookstore of the same name. He founded the Society of African Culture, and he organized landmark international conferences of black artists and intellectuals in Paris in 1956, Rome in 1959 and Dakar in 1966. Diop also cultivated a self-consciously Catholic strand of negritude that used all of these platforms to push for a new, more inclusive vision of Catholicism.

Beginning in the late 1940s, Diop was a tireless advocate for the reform of his adopted faith, and he gained the ear of Popes John XXIII and Paul VI. During the Second Vatican Council, he organized a standing lobby in Rome of the Catholics of the Society of African Culture. In 1963, in the midst of the council, he lamented on Vatican radio that African Catholics had to “borrow theological thought, spirituality, liturgy” from the West and expressed his wish that they be able to “express their African personhood at the very heart of Catholicism.”

Diop felt it was time for Africans, long on the receiving end of missionary instruction, to give some of their own wisdom to the church. He cited, for example, the openness toward Islam that characterized the Catholics of his native Senegal. This idea was advanced during the council by the young African archbishop of Dakar, Hyacinthe Thiandoum, and was reflected in its final teachings.

There was an important connection, therefore, between the decolonization of Africa and the reorientation of Catholicism at the Second Vatican Council. Yes, there were the symbolic gestures of canonizing African saints, or the elevation of Paul Zoungrana, the first francophone African cardinal, who read one of the council’s closing messages to the faithful in 1965.

Yet there was also the spirit of dialogue with other faiths, greater openness to the world beyond Europe and solidarity with the impoverished peoples of the developing world. African Catholic intellectuals insisted that they had knowledge, born of their unique cultures and of their experience of colonization, to share with European Catholics. The hierarchy listened to them, which set the stage for the church’s rapid expansion in Africa.

It does not follow, however, that African Catholics are now aligned with progressive Europeans, even though the two groups were allied against colonialism and racism in the 1950s and 1960s. On the contrary, many, though certainly not all, of today’s African prelates, clergy and laity are more socially conservative than their European counterparts, and some African Catholic leaders are skeptical of Francis. Cardinal Robert Sarah, a prominent traditionalist from Guinea, has denounced the “idolatry of Western freedom” as an “Apocalyptic beast” and has criticized same-sex marriage, gender fluidity, divorce, abortion and euthanasia as vital threats to the family.

Leftist European and American Catholics are often dismayed by such strident points of view, yet it is important to remember that Diop, regardless of whether he would have agreed with Sarah, had argued that African Catholics should not have to conform to prevailing European ideas and values.

Given the growth of the faith in Africa, it seems reasonable to expect that an African may be in Francis’s seat before another two generations pass, and perhaps much sooner. It is hard to see how European dominance of the College of Cardinals can persist indefinitely, given the demographics of the church. African leadership could take the church in a more progressive direction in some ways, but it might do quite the opposite in others. The only certainty is that while all roads still lead to Rome for now, the historic seat of the church is increasingly on the remote periphery of a new Catholic empire of the global south.