Though he helped design some of the region's most significant buildings, including Boston City Hall and the American Academy of Arts and Sciences in Cambridge, Gerhard Kallmann had little use for the attention that came with being one of Boston's greatest architects.
"Unlike painters or poets, architects themselves are not relevant to their work, and therefore should be anonymous," he told the Globe in 2004.
There was little chance of that happening in a career that began with a flourish designed for the history books.
Fifty years ago, neither Mr. Kallmann nor his friend and would-be partner, Michael McKinnell, had designed buildings under their own names.
Teaming together, they entered a competition to envision a new City Hall.
Their proposal was chosen from among some 250 entries.
In the half-century since, their creation has drawn lavish praise and savage attacks. City Hall still stands like a fortress, however, along with the reputation the partners carved out, with building after building, as versatile architects of vision and substance.
Mr. Kallmann, who was already in his mid-40s when his City Hall design turned him into an architect for the ages, died Tuesday in Mount Auburn Hospital of complications of a stroke he suffered a few days earlier.
He was 97 and lived in Cambridge.
With McKinnell, he created the City Hall design when Boston was down on its heels and, like many cities, in need of dramatically transforming its urban center.
"I think the work itself is one of the key icons of the last half of the 20th century," said Preston Scott Cohen, who chairs the department of architecture at the Harvard Graduate School of Design.
"Because of the importance of the building and because they were unknown, they were immediately turned into national figures by doing this," Cohen said. "It almost makes them seem like heroic figures. I can see these guys scrapping to achieve something so amazing. It must have just seemed so completely unbelievable at the time."
In 1976, for the bicentennial year, the American Institute of Architects polled distinguished architects, critics, and historians, asking them to choose the best buildings in US history. Boston City Hall tied for seventh with Trinity Church and was the highest-placing building designed by living architects.
Mr. Kallmann and the Boston firm he helped found, Kallmann, McKinnell & Wood, won numerous awards, particularly for City Hall and the American Academy of Arts and Sciences, but many outside their field have been less kind.
More than once Mayor Thomas M. Menino tried to rid himself of City Hall and its Brutalist architecture style and build a new one elsewhere.
Then there was the opinion of a passerby the Globe interviewed in 2006, who damned the design with the faintest of praise.
"It is ugly, but it's just something that's always been there," she said. "That's like trying to rip down Fenway Park."
With lasting patience to match his creation's enduring presence, Mr. Kallmann was unperturbed.
"City Hall is unpopular just now," he said in 2004, "but we can wait."
Born in Berlin, Gerhard Michael Kallmann left Germany with his family in 1937. Before fleeing the Nazi regime, he had begun to study law, his father's field.
"Hitler liberated me from a profession I didn't like," he told the Globe in 1992.
Settling first in England, he studied at the Architectural Association in London. Moving to the United States, he taught in Chicago and New York City and was an associate professor at Columbia University when he met and befriended McKinnell, who was finishing graduate work.
"He said, 'There's no architecture of the kind we want our students to build; we must enter a competition,' " McKinnell recalled. "As if by fate, the City Hall competition was announced two weeks later."
The commission brought them to Boston, where the concrete structure they created was "one of the handsomest buildings around and, thus far, one of the least understood," critic Ada Louise Huxtable wrote in The New York Times.
To many, City Hall remains inscrutable, but Mr. Kallmann was never troubled by those who demean his design.
"Any significant building makes demands so that it cannot be taken for granted; it should be a challenge," he told the Globe in 1991.
"You can make things too easy, so that there's nothing to resist you," he added. "The marvelous thing in life is to find a slight bend, as the torrent in the mountain that has to make a detour. When the way is clear, we enjoy the eddy. Without it, life is banal and obvious."
In the years since finishing City Hall, Mr. Kallmann's firm dotted Greater Boston and beyond with notable buildings. He was most involved in designing the Boston Five Cent Savings Bank, the gymnasium at Phillips Exeter Academy, the Becton Dickinson corporate campus in New Jersey, and Hauser Hall and Shad Hall at Harvard.
"He and his firm really set a very high standard for the architecture they did," said Laura Wernick, president of the Boston Society of Architects and a principal at HMFH Architects in Cambridge. "They had a clear vision for what design excellence is, and their buildings all reflected that, so it's the passing of an era I would say."
Other than City Hall, the project that drew the most attention to Mr. Kallmann was the American Academy of Arts and Sciences.
Completed at the beginning of the 1980s, the design won awards and "and kicked off a new career" for Mr. Kallmann's firm, Globe architecture critic Robert Campbell wrote in 1992.
Campbell began a Sunday Magazine profile of the firm by laying out the essential contradiction of Mr. Kallmann's career:
"Consider this: Boston City Hall is one of the least-loved buildings in Massachusetts, maybe one of the least-loved buildings in the known world. Yet the guys who designed it are the best architects in Boston."
In the earlier years after City Hall, Mr. Kallmann also taught at Harvard, and "will be remembered as much as a teacher," McKinnell said.
"I think everyone with whom he came into contact, either as an architect or a teacher or on social terms, was profoundly impressed by his culture as a human being, his sense of civility, his extraordinary range of learning, and his total sense of engagement with a pursuit of a full life."
Mr. Kallmann, who didn't marry, was the second of four siblings. He leaves a sister, Marlise Danziger of Westchester, N.Y.
A service will be announced.
Eduard Sekler, the Osgood Hooker professor of visual art emeritus at the Harvard Graduate School of Design, said architects and lovers of good design come to Boston from all over the world to see Mr. Kallmann's buildings.
"He really leaves a wonderful legacy, which one hopes will be honored through the generations," Sekler said. "We have had great architects in New England, and he is one of them. It became clear to me that he was, in a quiet way, an impressive, powerful personality who cared about the spiritual value of good design."
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