The Chicago-born pope was welcomed by huge crowds in the coastal city, on the final leg of his South America tour.

Pope Leo has made an emotional return to his former diocese of Chiclayo in Peru, where large crowds welcomed their former bishop exactly one month after he had lung cancer surgery, and he thanked them for their support during his recovery.

“As I look at your faces, a prayer of thanksgiving to the Lord arises in my heart for the blessing you have been and continue to be in my life,” he said.

About 500,000 people gathered for Mass at Pampas de Pimentel, a desert park just outside of Peru’s fourth-largest city, according to estimates from the Vatican, while another million lined his motorcade route.

Before he was elected pope, Leo had spent about two decades working in Peru as a missionary priest and served as bishop of Chiclayo, where he is still known as “Padre Roberto” and where his image is ubiquitous, from 2015 to 2023.

In Chiclayo, a coastal city of about 620,000, Leo earned a reputation for staying close to poor communities during times of crisis, including when the region was hit with devastating floods and the COVID-19 pandemic.

Some had camped overnight to see him, while others walked in the hot sun to avoid bumper-to-bumper traffic to get to the open-air Mass.

As he rode in his popemobile, people in the crowd waved yellow and white Vatican flags and shouted, “The pope is from Chiclayo.”

“What a joy it is to return to Chiclayo,” said Leo at the start of his homily.

Originally from Chicago and formerly known as Robert Francis Prevost, Leo also holds Peruvian citizenship and declared the country his homeland on Wednesday.

Peru is the final stop of his 12-day, three-country South America tour, coming after visits to Argentina and Uruguay. Approximately 12 million people have come to see him at public events so far.

Last month, he underwent surgery for lung cancer, amid fears that the trip would have to be cancelled. But doctors have said the cancer was localised, had not spread, and would not require further treatment.

Leo will stay in the Chiclayo area until Sunday, leading eight events, including a private dinner with the priests he oversaw during his time as bishop.