Here are 6 times when popes shaped history, for better or worse.

“It matters a lot that we have a pope and a spiritual leader whose heart is for migrants,” Cardinal Pablo Virgilio Siongco David of the Philippines said at a news conference. “And I think he will sustain the direction of Pope Francis.”

The morning after his surprise election, Leo returned to the Sistine Chapel to say his first Mass as pope. Evoking the teachings of Francis, his predecessor, he delivered a homily rich in theological references and said that a loss of religious faith had contributed to “appalling violations of human dignity” around the world.

He will soon confront urgent questions about the church’s direction, including a rising right wing in U.S. Catholicism that was highly critical of Francis.

Addressing a crowd from the balcony of St. Peter’s Basilica on Thursday, Leo spoke of “building bridges” but gave little overt indication of how he would govern the church. His first unscripted chances may come on Monday, when he holds a rare news conference with journalists.

Here’s what we’re covering:

• Who is Pope Leo XIV? Despite his American roots, Leo, born Robert Francis Prevost in Chicago, transcends borders. He served for two decades in Peru, where he became a bishop and a naturalized citizen, and then was appointed to one of the most influential posts at the Vatican by Francis, who made him a cardinal in 2023. Read more ›

• Why Leo? A pope’s choice of his papal name is always cloaked in symbolism. In Pope Leo’s case, it may also have been a clear and deliberate reference to the last Leo, who led during a difficult time for the Roman Catholic Church and helped usher it into the modern world. Read more ›

• Papal path: While the selection of an American pope was a shock to some, other parts of Leo XIV’s background make his election less surprising. He spent decades working with the poor in Peru, then led the Vatican office that selects and oversees the more than 5,000 Roman Catholic bishops around the world, giving him Vatican connections and an important say in the church’s direction. Read more ›

• An Augustinian pope: The new pope has spent most of his life as a friar in the Order of St. Augustine. Experts said that a commitment to two elements of Augustinian teaching — missionary outreach and listening widely before making decisions — could shape his approach to the papacy. Read more ›

Here are six eras when the papacy helped to shape history:

The fall of Rome

Catholicism became the official religion of the Roman Empire nearly a century before the fall of Rome. But the authority of the Pope actually increased when the Western Roman Empire began to decline in the 5th century.

In 452 A.D., Pope Leo I is said to have met Attila, the ruler of the nomadic Huns, at the gates of Rome when Attila was planning to sack the city. While historians debate the veracity of the story, many believe the pope’s pleas kept the Huns, who were most likely from Central Asia, from destroying Rome.

The influence of the papacy grew when Romulus Augustulus, the last Roman emperor, was deposed in 476 A.D. Pope Simplicius filled the void left by the imperial administration, and defended the city of Rome from Germanic invasions until his death.

Charlemagne and the Holy Roman Empire

Charlemagne, a medieval emperor who ruled much of Western Europe in the 8th and 9th centuries, was known for his brutal military campaigns and his steadfast defense of Christianity.

Charlemagne gave financial resources and land to the church and conquered the Lombard kingdom, which increased the power of the pope. In turn, Pope Leo III made him the emperor of the Holy Roman Empire.

It was a mutually beneficial coronation, and reinforced the strength of both Charlemagne’s influence and the pope’s imperial power. That authority would be wielded by the papacy for centuries.

The Crusades

In 1095, Pope Urban II gave a sermon in France calling for a military expedition to help the Greek Orthodox Church of the Byzantine Empire reclaim Jerusalem, which was then ruled by a Muslim caliphate. This began the first of a series of crusades that continued into the 13th century.

The military campaigns were extraordinarily bloody and fundamentally reshaped Europe and the Middle East.

The Age of Discovery

The papacy was a driving force in colonialism in the Americas.

A year after Christopher Columbus made landfall in North America in 1492, Pope Alexander VI, who was from Spain, issued a document titled “Inter Caetera,” which urged that “the Catholic faith and the Christian religion be exalted and be everywhere increased and spread.” That official decree became a justification for Christian colonization around the world.

The Vatican formally repudiated the decree in 2023 after decades of demands from Indigenous peoples.

The Reformation

The Protestant Reformation posed a direct challenge to the Catholic Church, which had held sway in much of Western Europe for hundreds of years. The movement is said to have begun in 1517 when Martin Luther, a monk, nailed a thesis denouncing elements of Catholic religious practice to the door of a church in Wittenberg, Germany.

The reformation gained ground in England in the 1530s when King Henry VIII — unable to get papal approval for his divorce from Katherine of Aragon so he could marry her lady-in-waiting, Anne Boleyn — broke from he Church.

Decades of conflict swept across Europe in the wake of the Reformation, in part fueled by disagreements between the Catholic Church and Protestant denominations over interpretations of the Bible and religious practice.

The fall of Communism

Joseph Stalin put his finger on the limits of papal authority when he asked derisively: “How many divisions has the pope?”

But even without military power, or any formal political power, the Catholic Church played an important role in the end of Communism. Pope John Paul II is credited with helping to create the conditions for the rise of Poland’s Solidarity labor movement, which led to the downfall of the Communist regime in that country.

This helped initiate the collapse of other Communist governments in Eastern Europe and the fall of the Berlin Wall in 1989.

Pope John Paul II was the first pontiff from Poland, a deeply Catholic country, and during his first visit there as pope, in 1979, he electrified the nation with his message that people should not be afraid. On the night he died in 2005, Poland’s former president, Aleksander Kwasniewski, said on national television, “We wouldn’t have had a free Poland without him.”

These and other whimsical suggestions started popping up on social media moments after Robert Francis Prevost’s Chicago roots came to light on Thursday.

“Canes nostros ipse comedit,” the marquee at Wieners Circle, a famous Chicago hot dog joint, joked in Latin. “He has eaten our dogs.”

Chicago drips with personality and has larger-than-life cultural figures and its fair share of corrupt politics, all of which are mixed with a touch of little-brother syndrome, making it a uniquely meme-able city. The food is polarizing, the history is stranger than fiction, and the traditions — like dying the river green on St. Patrick’s Day and playing softball without gloves — are somewhat bizarre.

“We definitely don’t take ourselves too seriously,” said Shermann Thomas, 43, a Chicago historian who also goes by the name Dilla. “The only rule is we don’t want anybody else talking crap about us.”

If the new pope found himself scrolling through social media, he would perhaps get a chuckle at the memes that ribbed Chicago for its quirks and poked at the paradox of a modern city entwining with a 2000-year-old tradition.

The jokes were so plentiful that people started posting their drafts of jokes that didn’t quite make the cut.

“The existence of Chicago Pope implies the existence of MLA Pope and APA Pope,” a user posted. Another user joked, “Chicago Pope, Tuesdays on NBC.”

In a city filled with diehard sports fans who have had little to celebrate of late, the sports jokes wrote themselves. Could this be the first time a pope has ever listened to “The Super Bowl Shuffle” or screamed at Steve Bartman? What is his opinion about the Chicago Bulls trading Elton Brand for Tyson Chandler?

“Daaaaaa Pope,” the Chicago Bears’ quarterback Caleb Williams posted on X.

Artificial intelligence, which is usually contributing to brain rot or helping high school students cheat, was working overtime at making some quality memes. Fake images of the pope baptizing an Italian beef sandwich and wearing a Chicago Bears cassock circulated.

For Mr. Thomas, the city historian, a lot of the city’s humor comes from how many different cultures fit themselves inside such a small area. Only Chicago could be home to Al Capone, the Latin Kings and the pope, he said.

This story could go on for another 500 words, filled with silly Chicago pope jokes. And it would be delightful. But we’ll leave you with perhaps the most relatable meme of the day:

“The Popemobile just cut you off on I-94.”

But he also broadened his reach, saying that he wanted peace to “enter your hearts, reach your families and all people, wherever they are; and all the peoples, and all the earth.”

That, suggested historian Gian Maria Vian, was a reference to Pope John XXIII, a hero to many liberal Catholics for opening the church to the modern era with the Second Vatican Council. In 1962, in the final months of his papacy, John appeared on the balcony and delivered off-the-cuff remarks now known as the “moonlight speech,” in which he told his listeners to hug their children when they got home and say, “This is a hug from the pope.“

As Leo addressed a rapt crowd in St. Peter’s Square on Thursday, he twice urged them to be “without fear,” an echo of John Paul II’s message at his 1978 inauguration Mass, one that expressed a central theme of his pontificate: “Do not be afraid. Open, I say open wide the doors for Christ. To his saving power open the boundaries of states, economic and political systems, the vast fields of culture, civilization, and development.”

Leo also reprised a reconciliation theme dear to Pope Francis, who died on April 21. Leo urged his listeners “to build bridges with dialogue and encounter so we can all be one people, always in peace.”

Mr. Vian pointed out that the word “pontiff,” a frequently used alternative to “pope,” derives from the Latin “pontifex,” meaning “one who builds bridges.”

“The pope IS the builder of bridges,” he said.

(Francis used the idea in reverse, as well. In 2016, returning from a visit to Mexico, he responded to a reporter’s question about President Donald J. Trump’s promises to deport more immigrants and force Mexico to pay for a border wall by saying: “A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian.”)

In his comments on Thursday, Leo repeatedly stressed the importance of outreach and connection, saying: “We have to look together how to be a missionary church, building bridges, dialogue, always open to receiving, with open arms for everyone, like this square, open to all, to all who need our charity, our presence, dialogue, love.”

Indeed, according to the Vatican, the Baroque architect Gian Lorenzo Bernini conceived of the colonnade that embraces the central piazza of St. Peter’s Square to “welcome with maternally open arms, Catholics, so as to confirm them in their faith; heretics, to reunite them to the Church; and infidels, to enlighten them in the true faith.”

Leo concluded his remarks by referring to the special prayers Catholics dedicate on May 8 to Our Lady of the Rosary, honored by a pontifical shrine dedicated to the Virgin Mary in Pompeii. “Let us pray together for this new mission,” Leo said, “for the whole church, for peace in the world, and let us also ask Mary, our mother, for this special grace.”

In a statement, Msgr. Tommaso Caputo, the archbishop of Pompeii, said he was touched that the new pope “had a thought for our virgin” in his first moments on the balcony. Monsignor Caputo noted that the current pope’s namesake, Leo XIII, had written multiple encyclicals dedicated to the rosary, the Catholic prayer series invoking Mary that is counted out on beads.

Leo XIV, the 267th pope of the Roman Catholic Church, concluded his comments by leading the assembled in the Hail Mary.

When he was introduced to the world, the new pope — who speaks five languages and is a naturalized citizen of Peru — emphasized his pluralistic background, making a point of speaking in Italian (representing his new constituency) and Spanish (his old one). He spoke no English and made no reference to the United States, even as some Catholics in St. Peter’s Square excitedly waved U.S. flags. (On Friday, he spoke briefly in English when he delivered his first homily.)

There are indications that the first American pontiff disapproves of some of the Trump administration’s hard-line stances. A social media account under his name has reposted messages critical of the president’s positions on issues including immigration, gun control and climate change. In February, the account shared a link to an article in The National Catholic Reporter titled “JD Vance Is Wrong: Jesus Doesn’t Ask Us to Rank Our Love for Others.”

“We have this powerful moral voice that is going to be able to potentially confront the other most powerful American voice,” said Charlie Sykes, an anti-Trump conservative who is Catholic. “Donald Trump bestrides the world as the ugly American, and now we have another prominent American who is able to confront him.”

Mr. Sykes said Pope Leo’s advocacy on behalf of migrants, in particular, could challenge Mr. Trump, who has pursued an aggressive campaign to deport them as quickly as possible.

“Part of Donald Trump’s appeal is that he is the great champion of Christendom and now he’s going to have to explain that to a fellow American who is the pope,” Mr. Sykes said. “There are very few, if any, figures that have the platform and the voice of the Holy See.”

John Prevost, the pope’s brother, told The New York Times in an interview that he did not think his brother would shy away from voicing his disagreements with the president.

“I know he’s not happy with what’s going on with immigration,” he said. “I know that for a fact. How far he’ll go with it is only one’s guess, but he won’t just sit back. I don’t think he’ll be the silent one.”

Still, Vatican analysts say Pope Leo is more reserved than his predecessor, and while they expect him to continue to defend migrants and the poor, some do not expect him to do so in as outspoken a manner as Pope Francis.

Mr. Trump and his supporters have also found aspects of the new pope’s background that excite them, including his ardent anti-abortion advocacy and his opposition to a government plan in Peru to add teachings on gender in schools.

“He’s said and done some mixed things in the past,” said John Yep, the chief executive of Catholics for Catholics, a group that supports Mr. Trump. “Let’s see how he does. I don’t want to rush to judgments right off the bat.”

In the hours since Pope Leo’s selection, the president has had only praise for the church’s new leader. Mr. Trump and Vice President JD Vance both congratulated him in posts on social media and celebrated his American heritage.

“The president made his reaction to Pope Leo’s announcement yesterday very clear,” Karoline Leavitt, the White House press secretary, told reporters on Friday when asked about the pope’s comments. “He’s very proud to have an American pope.”

It is unclear if either Mr. Trump or Mr. Vance had been aware of Pope Leo’s criticism of their policies, but some of the president’s most strident supporters have already registered their displeasure.

“He is anti-Trump, anti-MAGA, pro-open Borders, and a total Marxist like Pope Francis,” Laura Loomer, the far-right activist who has persuaded Mr. Trump to fire some of his aides for not being loyal enough, wrote on X. “Catholics don’t have anything good to look forward to. Just another Marxist puppet in the Vatican.”

Representative Nancy Pelosi, the former House speaker and a devout Catholic, praised Pope Leo’s commitment to the poor and said she hoped he could unite American Catholics across partisan divides.

“His values-based vision for the church is quite different from what we’re seeing from some leaders, if you call them that, in our country, but I don’t expect him to be engaged in a political debate with the president of the United States,” she said in an interview.

Even though Pope Leo is an American by birth, he has spent most of his adult life outside the country, and now as the head of state of another nation, it remains to be seen what relationship he will have with the United States. Pope Francis, who hailed from Argentina, never returned to his place of birth after becoming the church’s leader.

American cardinals said at a news conference on Friday that Pope Leo’s American identity was not a factor in his selection. When he was announced, the Vatican made no mention of his U.S. nationality, instead introducing him as the second pope from the Americas.

Cardinal Wilton Gregory, the archbishop emeritus of Washington, D.C., said the conclave was not seen as a “continuation of the American election.”

“It wasn’t an election conclave,” he said. “It was a desire to strengthen the Christian faith among God’s people.”

Joe Donnelly, the U.S. ambassador to the Holy See during the Biden administration, said Pope Leo’s selection transcended any nationality, but would also serve to demonstrate American values on the world stage.

“I think Pope Leo will be a wonderful reflection of America, of Chicago and all of our hardworking people,” Mr. Donnelly said. “He is a prototype of the American success story, working hard, studying hard and being kind to others.”

The cardinals’ selection of an American pope defied the prevailing belief that the church would not choose a leader from the global superpower. In the days leading up to the conclave, Catholic commentators speculated that Mr. Trump’s disruption of the global political and economic order made a U.S.-born pope even more unlikely.

Indeed, some spectators gathered in St. Peter’s Square on Thursday were bewildered when his identity emerged.

“Un Americano?” several muttered in Italian.

“I am surprised and disappointed,” said Adam Mocarski, 31, from Poland.

The immediate disillusion was not directed at the new pope himself, but appeared to reflect how much Mr. Trump has roiled international sentiment toward America.

“Trump wants to divide,” said Francesca Elicio, 29, a theater producer from Rome. “Trump has a negative effect not just on America, but on other countries. Perhaps the idea was to have an intermediary who can save not just the church, but the whole world.”

Some analysts have posited that the cardinals selected Pope Leo precisely because of Mr. Trump. The president agitated many Catholics, even some of his allies, when he posted an A.I.-generated image of himself dressed as the pope after Pope Francis died.

“The president might well be right to claim credit for the selection, at least in part, given the photo he posted on social media,” said Rocco Palmo, a Catholic church analyst. “The choice of Leo is the cardinals’ way of saying, ‘This is our process and we decide what is Catholic, not the White House.’”

Matthew Mpoke Bigg and Elizabeth Dias contributed reporting from Vatican City.

United States law allows dual citizenship. According to the State Department, a dual citizen who became a foreign head of state would not necessarily lose American citizenship if he or she wanted to keep it.

And the Holy See lets a Pope retain other citizenships. Pope Francis retained his Argentine nationality and even renewed his Argentine passport in 2017. His two predecessors also retained their native citizenship.

The State Department explains on its website that it will “actively review” cases of foreign heads of state wishing to retain American citizenship, while warning that such cases “raise complex questions of international law,” including ones related to immunity from American legal jurisdiction.

Foreign leaders who want to retain American nationality can notify the State Department of their preference, the department says, while a person who wants to give up citizenship must inform a U.S. embassy or consulate “and follow the required steps.”

In rare cases, U.S. citizens have served as foreign heads of state. Somalia’s former president, Mohamed Abdullahi Mohamed, was born in Somalia but lived in the United States and became a naturalized American citizen before his 2017 election. He renounced his American citizenship two years later, amid charges of dual loyalties.

Vatican City, where the pope resides, is governed by the Holy See, which is considered a sovereign government. It is recognized by the United Nations, although it chooses to hold permanent observer status there rather than full member status, “due primarily to the desire of the Holy See to maintain absolute neutrality in specific political problems,” the Holy See’s mission to the U.N. says on its website.

Pope Leo is also a citizen of Peru, which allows dual citizenship, though it is unclear whether it has laws applicable to a citizen becoming a foreign head of state.

The State Department did not immediately respond to a request for comment about Pope Leo’s circumstances, and the Vatican has not publicly indicated his plans.

In “Laudato Si,” a sprawling call to action, Francis recognized climate change as both a social and environmental crisis and emphasized that its greatest consequences were shouldered by the poor. Rich countries like the United States and the United Kingdom are responsible for a disproportionately high share of historical emissions, and major fossil fuel producers like Saudi Arabia and Canada have some of the highest per capita greenhouse gas emissions today.

Leo did not mention climate change in his first speech as pope on Thursday. (Neither did Francis in his first remarks in 2013). But as a cardinal, Leo spoke at a seminar last year at which he urged the world to move from “words to action” on the issue. “Dominion over nature” should not become “tyrannical,” he told the gathering at the Vatican.

He has also praised the Vatican’s use of solar panels and electric vehicles.

The past 10 years have been the 10 hottest in nearly 200 years of record-keeping, and 2024 was the hottest year ever recorded. Global temperatures have risen around a degree and a half Celsius above preindustrial averages, and scientific consensus has attributed a majority of that rise to the heat-trapping effects of greenhouse gas emissions, which largely come from the burning of fossil fuels.

What exactly are saints? They are the Catholic Church’s superheroes — men and women whom it considers to have lived lives of such heightened virtue that they are worthy of imitation. Broadly speaking, they attain the honor through martyrdom or miracles, though there are other recognized pathways. Usually it takes a long time for the church to determine sainthood: The average time from death to canonization is 181 years.

In fact, until Pope John Paul II changed it, there was a 50-year waiting period. Now, the rule is only five years, though it is John Paul II himself who has become the best argument against fast tracking a candidate.

Francis canonized John Paul II in 2014, just nine years after his death. Six years later, however, an investigation, also commissioned by Francis, found that John Paul II had chosen not to believe longstanding accusations of sexual abuse against the former prelate Theodore E. McCarrick, including pedophilia, allowing him to rise in the church’s hierarchy.

A reversal of the canonization, which historians struggle to recall ever happening, is implausible. Still, the fallout from the McCarrick report is likely slow down the cause for Francis’ canonization, as well as the causes of others high in the church hierarchy during the late 20th century and early 21st century, when the sex abuse scandal exploded in the church.

Kathleen Cummings, author of “A Saint of Our Own” and the head of a center on U.S. Catholicism at the University of Notre Dame, said the Vatican should wait at least 20 years before allowing Francis’ cause to proceed, giving historians enough time to do their work.

“Almost certainly the late pope, who loved the saints and canonized a record number of them, would frown upon an effort to launch his cause for canonization,” Ms. Cummings said. “He’d prefer that the time and resources be channeled toward helping the poor, the migrants, and others close to his heart.”

The pope, formerly Cardinal Robert Francis Prevost, grew up in the Chicago area. He attended a boarding school for boys near the city of Holland, Mich., that was run by the Augustinians. The school has since closed.

In 1977, he graduated from Villanova University, the premier Catholic university of the Augustinian order in the United States. That year, he entered the novitiate of the Order of St. Augustine in St. Louis. Four years later, at age 25, he made his vows to join the order, according to Vatican News, the Holy See’s news service.

The decision to join an order rather than become a priest in a diocese is crucial to understanding Leo’s approach to a life of faith, according to Sister Gemma Simmonds, an author and senior research fellow at the Margaret Beaufort Institute of Theology at Cambridge University.

A diocesan priest is charged with obedience to his bishop but is otherwise largely independent, she said, while a member of an order makes a commitment to live, pray, eat, worship and make decisions in community.

“The emphasis is on collaboration and community life,” said Sister Gemma, who belongs to the Congregation of Jesus, another Catholic religious order. “That’s very interesting for a pope, because it means that he is geared toward collaborative decision making.”

The Order of St. Augustine, one of many within the Catholic Church, has its own distinct character. It was founded in 1244, when Pope Innocent IV united groups of hermits in service to the church as a community of friars. The group committed to a lifestyle of poverty, and a mix of contemplation and pastoral service.

Augustinians look to one of Christianity’s most important early theologians, Aurelius Augustine, the Bishop of Hippo, who was born in what is now Algeria in the fourth century. Augustine is perhaps most famous for an autobiographical work called “Confessions,” which in part details his conversion to Christianity after an immoral youth.

He also wrote a guide to religious life, known as a rule, which is the cornerstone of the Augustinian order. It commits its members to “live together in harmony, being of one mind and one heart on the way to God.”

The order is divided into three branches — friars, nuns and lay members — and has a presence in around 50 countries, most notably in Latin America, according to its website, augustinians.org. Leo led the Augustinians, as Prior General, from 2001 to 2013.

On Thursday, the Augustinians welcomed the new pope’s election and said it would “renew our commitment as Augustinians to serve the Church in its mission.”

That mission, especially in Peru, defined the new pope’s career. As a priest, he first went to the country in 1985, working at the Augustinian mission in the northwestern town of Chulucanas. Over the following years, he moved into more senior roles at the Augustinian mission in the city of Trujillo, where he was also a professor of canon law and theology.

In those years, the country was plagued by violence fomented by the Shining Path, a Maoist guerrilla movement.

The legacy of some Christian missionary work has attracted criticism, not least in Latin America where over the centuries it helped promote conquest and colonization. While the church has wrestled with that legacy, the concept of mission, in the sense of reaching beyond the institution’s walls into communities that are often impoverished, retains a powerful hold on Catholic thinking.

John Allen, a veteran Vatican analyst, said that Leo’s experience as a missionary was likely part of what attracted the cardinals to him in the papal conclave.

“One of the things he did is to insist that the leadership of the mission becomes indigenous,” Mr. Allen said in an interview. “That reflects the heart of a missionary, and I think that is what the cardinals saw.”

“Welcome to Chiclayo, the land of the pope!” a flight attendant announced as a plane from Lima touched down on Thursday. Passengers burst into applause.

Pope Leo XIV spent much of his career outside the United States, arriving in northern Peru in 1985 at a time when internal conflict terrorized much of the countryside, killing many Peruvians and making the country an uncommon destination for foreigners.

He stayed, except for a brief stint in Illinois, until roughly 1999, according to an official biography. And then he returned again in 2014, becoming bishop of Chiclayo in 2015.

To be bishop, he was required by a diplomatic treaty between Peru and the Vatican to become a citizen of Peru — which he did.

The coastal city of Chiclayo, with a metropolitan population of about 800,000 people, is known in Peru for its good cooking — fresh ceviche, stewed goat and squash, duck and cilantro-infused rice. And in interviews with Peruvian news media, the pope — previously known as Robert Francis Prevost or simply “Monseñor Roberto” — has expressed a strong affinity for the region’s specialties.

The diocese of Chiclayo also encompasses highland and coastal regions far from the city and for decades before him, it was led by conservative bishops.

On Thursday, when the pope made his first public address from the balcony of St. Peter’s Basilica, there was one community he mentioned by name: his “dear Chiclayo.”

While many missionaries return to their country of origin after serving, the pope considered staying in Peru the rest of his life, said Elías Neyra, a friar and a coordinator for the Augustinian order in Latin America.

“He had told many of us that he did plan to live out his days here in Peru,” he said.

The U.S. Embassy in Peru celebrated his dual identity on social media: “From Chicago to Chiclayo.”

At sundown on Thursday in Chiclayo, the conversation was all about the “Peruvian pope.” In the cathedral in the main square, a crowd had gathered, singing hallelujah.

Outside, people had printed giant posters of Pope Leo and shouted “long live the pope!”

In a restaurant, a freestyle rapper who was performing for tips worked references to the new “chiclayano” pope into his lyrics.

Mariana Quiróz, 39, carried a framed picture of the pope blessing her baby cousin in 2015. Ms. Quiróz said she worked beside him in 2017, in parts of the region hard-hit by floods, and remembered him wading through the high waters to help out.

“He wasn’t a man of the desk but a man who worked with the people,” she said.

“People were suffering so much. Many were left homeless. And the father was there.”

The Rev. Elmer Uchofen, a priest in Chiclayo, recalled traveling long hours by car into the highlands with the bishop to reach parishioners. “We would talk in the car while I was driving,” Father Uchofen said.

“And he would listen quite a bit. He would arrive and he was very, very warm with the people, especially the people of the Sierra to whom he would offer his help.” He said he would deliver food and other supplies to remote areas, sometimes carrying sacks of rice himself.

“He always had a low profile. Very patient, very smiling,” Father Uchofen said. “He also said things firmly when he saw something that was not right or something that was not in accordance with the things of the Church.”

He said he thought that Pope Leo represented “a continuity” with Pope Francis, who emphasized compassion for the poor, and for migrants, and a need to bring the church to the people.

“It is not a radical change,” said Father Uchofen, “but to reinforce many things.”

In the center of Chiclayo, Juana Loren, 60, a church volunteer and part of a women’s prayer group at the cathedral called Adorers of the Blessed Sacrament, said that the pope — when he was a bishop — had confirmed her daughter.

She showed off photographs of her and the other women in her group with Leo, as well as a letter that he wrote to them in September to commemorate the group’s 23rd anniversary.

“He had a lot of holiness. We always saw it,” she said. “We used to joke and say: He is either going to become a saint or a pope.”

Elda Cantú contributed reporting from Mexico City.

But Bishop Prevost, now Pope Leo XIV, did not waver, the priest said: He mobilized local churches, clergy and lay leaders to feed, house and care for migrants.

That experience gives Pope Leo another link to his predecessor, Pope Francis, who made speaking out about the global migration crisis a foundational part of his pontificate.

Francis’ first papal trip was to the southern Italian island of Lampedusa, a frequent landing spot for boats carrying North Africans trying to reach Europe. Francis frequently cast a spotlight on refugees fleeing famine, natural disasters and war, and often expressed care and sympathy for migrants he described as vulnerable people seeking a better life.

Perhaps Pope Leo, who was born in Chicago, saw something of his own family history in the migrants’ stories: his grandparents immigrated to the United States from France and Spain, he told the Italian broadcaster RAI this year. Whatever his reasons, Father Vásquez said, when local church leaders in Chiclayo mobilized to offer care to the Venezuelans, “Monsignor Prevost supported this work.”

Father Vásquez outfitted space at his church for migrants to use as a shelter. The Rev. Luis Santamaría, another priest, set up a dining hall.

“At the national level, this was a big problem,” Father Santamaría said in an interview, with some people blaming Venezuelans for violent crime and robberies. “They were not always well regarded. Even here, in our parishes.”

Bishop Prevost convened lay leaders in the diocese to help organize a response. One was Yolanda Díaz, who set up a group to assist migrants and victims of human smuggling. She said she briefed the bishop on their progress every 15 days.

“We were overwhelmed by this situation affecting our migrant brothers,” Ms. Díaz said in an interview. “Monsignor Robert asked, ‘How are we going to respond? What are we going to do?’”

On Thursday, after Pope Leo was introduced at the Vatican, Ms. Díaz said she received a call from one of the migrants the church had helped in Chiclayo. The man now lives in another country but wanted to talk about the bishop who had supported him.

“He was so happy,” she said of the caller.