KNOCK, Ireland — He waded through a throng of believers here as a healthy 13-year-old, brought on a pilgrimage by his mother.
The husky, red-headed boy named Martin J. Walsh had once been stricken with cancer. At age 7, he was given two months to live. His mother made a vow: If the Lord spared her son, Mary Walsh would bring him to a shrine here that is venerated as the site where the Virgin Mary appeared on the stone wall of a country church.
Young Martin had become gaunt. That red hair fell out. But, then, radiation treatments and chemotherapy worked. The cancer, Burkitt’s lymphoma, retreated and after four years was gone.
So Mary Walsh journeyed to the west coast of Ireland with her son, the future mayor of Boston.
“I promised to take him, you see,” Mary Walsh said Wednesday at the shrine. “Martin was already healed when we came. But so many people have been healed here.”
They were back there Wednesday, mother and son.
The shrine at Knock stands as a sacred place for the Walsh family, whose roots are two hours south in Connemara. It is as much a part of their Ireland as the 400-year-old ancestral home in Rosmuc, the ancient stone walls crisscrossing the family land, or the air perfumed by the smell of burning peat.
It is evident, too, at the grave of the mayor’s paternal grandparents. A tablet from a gift store near the shrine leans against the faded Celtic cross that marks their grave. “Mum & Dad,” the tablet reads. “I prayed for you at Knock.”
“It’s part of my experience with Ireland,” Walsh said. “When I was a kid, my mother took me here . . . and I came here with my grandmother. It’s a big part of our faith and a big part of me being healed from cancer.”
Walsh’s stop at the shrine Wednesday came midway through his first trip as mayor to Ireland, where he spent several summers as a child. It has proved an emotional return, with Walsh overwhelmed by an outpouring of pride in his parents’ native villages.
The trip has also been a spiritual journey underscored by Catholic traditions. Walsh attended two Masses, celebrated entirely in the native Irish language, that were said in his honor at the churches of his mother and father.
On this day, they were in County Mayo, where Knock was a rural village in 1879 with a small country church and a few cottages. The region had endured famine and war.
On a rainy August evening, a fantastic vision appeared outside on the south wall of the church, according to the Rev. Richard Gibbons, rector of the National Marian Shrine.
The apparition included Mary, the mother of Jesus; his father, Joseph; and St. John the Evangelist. Beside them was an altar with a cross and the figure of a lamb. Angels hovered, said Gibbons. People watched in the pouring rain that night and prayed.
“Anybody and everybody that happened to come along the scene could see it,” Gibbons said. “Since then, it has developed into an international shrine.”
The church verified the accounts of 15 witnesses, Gibbons said, and multitudes flocked there. The shrine has demonstrated healing powers, the priest related. He pointed to the story of Marion Carroll, a woman afflicted with multiple sclerosis who had lost use of her legs.
During a pilgrimage to the shrine 25 years ago, Carroll felt a stirring, Gibbons said. When she returned home, she stood up unaided and drank a cup of tea, according to the account on the shrine’s website.
“She came in on a stretcher, and she walked out,” Gibbons said. “You don’t get much more dramatic than that.”
Knock has become an epicenter for religious tourism, with a sprawling campus that now covers more than 100 acres and draws 1.6 million visitors annually. A Knock priest, Rev. James Horan, pushed to build an airport and a new church large enough to accommodate 10,000 people; the sanctuary was blessed as a basilica by Pope John Paul II. There are hotels, bed and breakfasts, a campground for motor homes, and religious gift shops.
At Knock, Walsh and his family were greeted at the gate and offered a tour. Mary Walsh walked off on her own.
“She’s been here before,” the mayor said. “She’s going shopping.”
Mary Walsh said she visits the shrine every year when she comes home. She bought four pint-sized plastic bottles to fill with holy water from one of 18 spigots near the site of the apparition.
“Martin calls me all the time to see if I have holy water so he can give it to sick people,” she said.
In Walsh’s childhood home in Dorchester, every room is adorned with a crucifix. “My mother used to have gallons of holy water in the house,” the mayor said.
The original stone wall where believers say the vision appeared had to be replaced because pilgrims had chipped away so many pieces of rock as souvenirs. The shrine preserved one section of the original stone. It was that section where Mary Walsh briefly laid both her hands Wednesday.
The mayor paused to pray at the site of the apparition, saying a Hail Mary with his longtime girlfriend, Lorrie Higgins, and the priest. Walsh made the sign of the cross and placed a folded bill into an offertory slot. Then he ducked into a gift store to buy several copies of the Serenity Prayer and a new wooden rosary.
Walsh usually has rosary beads in his pocket, he said. His old rosary had been blessed by Pope Francis, but he gave it away Tuesday to a 12-year-old boy who has cancer. He often gives his rosaries away, he said, when someone else needs one.
“My faith helped me,” Walsh said. “Anybody that has cancer or an illness, a lot of it is medicine, but there are prayers and faith. It doesn’t have to be Catholic. It can be other religions. Faith is important. It absolutely makes a difference in people’s lives.”
Walsh carried the new rosary and prayer cards in a brown paper bag, which he held up for a priest.
“Will you give that a quick prayer?” he asked.
The priest made the sign of the cross over the bag.
Andrew Ryan can be reached at firstname.lastname@example.org.