By S.I. Rosenbaum, Globe Correspondent
The building at 63 Longwood Avenue in Brookline doesn't look much like anything special -- just a modest brick two-story, dating back to the turn of the century.
But to Cholthanee Koerojna, of Burlington, this unassuming building is the "Brookline Palace."
Within these walls, His Majesty King Bhumibol Adulyadej of Thailand took his first steps, said his first words. Here his father, the prince, cooked meals for fellow Thai students. The family played on the rooftop.
"I feel sometimes, when I stood in front of that place, I have goosebumps," Koerojna said. "I think back to 1928, imagine seing the children playing in front of the building ...we feel warm feelings just seeing that building."
On Sunday, October 18, Koerojna will preside over a ceremony to dedicate a plaque commemorating the king's time here, from 1926-1928. Buddhist monks will chant and daub the plaque with holy water, before Thai dancers perform on the sidewalk in front of the building. The ceremony is expected to start at 9:45 am.
It's a part of Koerojna's quest to find and mark the places where the king and his family stayed during their time in Massachusetts.
"I help people to learn about them, and I feel so proud," she said.
In Thailand, King Bhumibol (pronounced poom-mi-pon) is a beloved national hero whose portrait hangs in most households. As a child, Koerojna prayed before his portrait for good luck.
Most Thai are aware that the king was born in Cambridge, making him the only foreign-born monarch in the world.
"People (visiting the U.S.) stop and swing by Boston just want to see where he's born," said Sittithep Krajangsart, a cook at Rod Dee restaurant, not far from the Longwood building. "When you're feeling like 'Hey, this is the town where my king used to live,' it's really amazing."
But even many Thai don't know the details of how the king came to be born here, said Koerojna.
The king's father, Prince Mahidol of Thailand first came to Boston in 1916 to study public health at Harvard University and MIT. That was how he met his wife, a Thai nursing student at Simmons and a commoner, Koerojna said.
Prince Mahidol returned to Harvard to study medicine in 1926, this time bringing his family. In Boston, he wanted to be known not as royalty but simply as "Mr. Songkla," Koerojna said. Arriving in the city ahead of his family, he stayed at the YMCA, she said.
"He wanted to live simply, like many other Americans here," Koerojna said. "He didnt want to be different from any other people. He really put himself down to earth."
Prince Mahidol first tried to rent a house in Brookline, but was refused a lease because the landlord didn't want tenants with children, Koerojna. So the family ended up living on the second floor of the apartment building on Longwood Avenue -- the Brookline Palace.
In 1927 their third child was born at Mt. Auburn Hospital -- a boy they named Bhumipol Adulyadej. He would eventually ascend the throne in 1946, after the death of his older brother.
Now 82, King Bhumibol is something of a polymath. He's an accomplished jazz composer, and has patented a method for seeding rainclouds, to stave off droughts.
Like many of her countrymen, Koerojna feels a personal connection to the king.
"Thai people call the king a father," she said. "They feel, when I have problems, 'My father helps me.'"
In 2000, Koerojna, an administrator at Mass Bay Community College, started a project to clean up and renovate the small public square in Cambridge named for the king.
The square was re-dedicated with a new sign and monument in November, 2003.
But that was just the beginning.
Koerojna began to research the history of the royal family's stay in Massachusetts, and identified 10 historic sites where royalty lived at different times.
Over the summer, her nonprofit organization, the King of Thailand Birthplace Foundation, has affixed plaques marking most of the sites, including houses in Gloucester and Martha's Vineyard, two residences in Cambridge and one spot in Harvard Square.
On Thursday, they readied a plaque outside Mt. Auburn Hospital. And Koerojna plans to put up the final plaque next spring, on another house on Martha's Vineyard, now owned by the actor Tom Welling.
Most modern-day residents have been excited to find that their homes were once inhabited by royalty. Longwood resident David Stein, 28, said he found out about the building's history when workers asked to borrow his stepladder to put up the plaque by the door.
"I was surprised," he said. "It's a random fact but it makes our apartment a lot cooler."