The English conductor and violinist Sir Neville Marriner, the founder of the Academy of St. Martin in the Fields, circa 1965. (Erich Auerbach)

Neville Marriner, the British violinist-turned-conductor who founded the Academy of St. Martin in the Fields and built it into one of the most popular and widely recorded chamber orchestras in the world, died Oct. 2 at his home in London. He was 92.

The academy announced the death in a statement on its website but did not disclose the cause.

The ensemble began as a group of 13 friends playing baroque music for strings in Mr. Marriner’s living room, but it quickly grew larger and more ambitious. Its first public concert took place at its namesake church in London’s Trafalgar Square in 1958, and shortly thereafter, the group was invited to make its first recording.

It would turn out to be the first of several hundred albums credited to “St. Martin’s,” as it was customarily abbreviated. At least 200 of these were led by Mr. Marriner, initially with nods and gestures as he played the leading violin part and later from the podium.

The group’s soundtrack for the Oscar-winning Milos Forman film “Amadeus” (1984), devoted mostly to works by Mozart, became one of the best-selling classical recordings of all time, selling in the millions. “In those days, we were so rich we thought about building our own concert hall, converting an old power station in East London,” Mr. Marriner later recalled.

Neville Marriner circa 1965. (Erich Auerbach)

In fact, the ensemble had been successful almost from the beginning, although — in the United States, at least — it was known for its best-selling records and a near-constant presence on classical radio rather than any American performances, of which there were none until 1980.

As the critic and broadcaster Nicholas Kenyon observed in 1983, “Their sound was so well known on radio stations that Stereo Review once ran a cartoon in which a radio announcer was saying, ‘. . . played now by the Academy of St. Martin in the Fields . . .’ and a parrot in the room added, with a glazed look in its eyes, ‘Neville Marriner conducting.’ ”

Mr. Marriner took a deep interest in the recording process. The British critic Edward Greenfield once called him “a recording manager’s dream, because he understands technical problems as well as most technicians, and accepts the necessity of retakes.”

“It’s the sound of the Academy that made it celebrated around the world,” Mr. Marriner reflected in an interview he gave to the Guardian newspaper for his 90th birthday in 2014. “We wanted some clarity in the texture and vitality in the tempi. Early music at that time had been slow, thick, cloudy and taken very seriously, like an ancient relic.”

Indeed, Mr. Marriner and his group were part of a huge revival of scholarly and popular interest in music of the 18th and early 19th centuries that began in the 1960s and has continued to this day.

Washington Post arts critic Philip Kennicott once described the original appeal of the St. Martin’s performances and its interpretation of classics. “The Academy played them like chamber music,” he wrote in 2001, “with reduced forces and an emphasis on clarity; it also played them fast, which produced a broad architectural overview. This was revelatory in an age when conductors often got bogged down milking each phrase for its maximum romantic yield.”

By the 1980s, a new group of scholar-performers had come along. Artists such as Trevor Pinnock, Roger Norrington and the late Christopher Hogwood prided themselves on playing in a style that they thought baroque composers might have recognized — on period instruments, with valveless horns and vibrato-less strings made from gut, all in strict rhythmic patterns.

It was all rather austere for Mr. Marriner, and his work fell out of favor among many musicologists, if never with the general public. Writing in The Post in 1988, critic Joseph McLellan observed that “Marriner and his Academy of St. Martin in the Fields orchestra [were effectively] driven from the 18th-century repertoire that made them famous by the purist demands of the early-instrument movement.”

Mr. Marriner declared himself unbothered by the change in tastes. “The Academy decided, ‘To hell with this.’ We decided to drop that sort of repertoire or give away as much of it as we could,” he told McLellan. “We moved on to Beethoven, Schubert and Mendelssohn. Suddenly you find yourself in the middle of the 19th century or in the late 19th century, and you’re becoming a much, much larger orchestra. This is what happened to us.”

Later St. Martin’s recordings would include the complete symphonies of Ludwig van Beethoven, Franz Schubert, Robert Schumann and Peter Ilich Tchaikovsky as well as 20th-century British works by Edward Elgar, Ralph Vaughan Williams and Benjamin Britten.

For a conductor, Mr. Marriner was unusually self-effacing, a trait that endeared him to his colleagues. Asked once for his proudest claim about the orchestra, he gave a simple answer: “We decided always to have good players and never to go on the platform under-rehearsed.”

Neville Marriner was born in Lincoln, England, on April 15, 1924, the son of a carpenter. It was a musical household — “You could say that family music was for us what television is for most people today,” Mr. Marriner recalled in 1968 — and he entered the Royal College of Music on a full scholarship at age 15.

During World War II, he served in the Royal Navy but was demobilized because of a kidney ailment. He returned to the music college, where he decided that he was not bound for the life of a concert virtuoso. And so he became a well-known collaborative artist, playing in a duo with the harpsichordist Thurston Dart, as well as in string quartets and trios.

He also served as a freelance violinist with the Philharmonia Orchestra, in London, where he played under the baton of Arturo Toscanini, Wilhelm Furtwängler, Herbert von Karajan and others. From 1956 to 1958, he was the principal second violinist in the London Symphony Orchestra.

The decision to name the ensemble the Academy of St. Martin in the Fields was a practical one.

“It was the place where we gave our first ever concert back in 1958, so there’s significance in that,” Mr. Marriner told the London Daily Telegraph in 2014. “But the real reason we took the name was that the vicar let us rehearse there for free so long as we publicized the church. That was the deal. And it was his idea that we should be an ‘academy’ rather than the ‘chamber orchestra’ we’d originally planned to call ourselves.”

St. Martin’s was originally intended to be led solely by Mr. Marriner from the violin, but as it grew in size and began to play more complicated works, closer control was necessary. “Having been refugees from the tyranny of someone waving a stick, they made me turn from poacher to gamekeeper, and I did it,” he said.

Mr. Marriner had by then visited the United States, where he studied conducting with Pierre Monteux at a summer retreat the older man established at his home in Hancock, Maine. “The actual mechanics of conducting are not difficult,” Mr. Marriner decided. “It’s getting the confidence. It’s like taking a driving test.”

After recordings made him famous, Mr. Marriner gradually expanded his conducting career beyond the Academy of St. Martin in the Fields. In 1969, he became the first music director of the newly established Los Angeles Chamber Orchestra, a position he held until 1978. He was the music director of the Minnesota Orchestra from 1979 to 1986 and enjoyed a long association with the Stuttgart Radio Symphony Orchestra, in Germany, culminating in three years as principal conductor, from 1986 to 1989.

As Mr. Marriner’s orchestral career grew busier, the Academy was often led by other musicians, notably Iona Brown, Murray Perahia and, most recently, Joshua Bell, who was named the group’s second music director in 2011. But Mr. Marriner kept up his ties with the Academy of St. Martin in the Fields to the end and was eventually named life president. He conducted the group in May 2015, when he led a benefit concert in London for victims of the Nepal earthquake.

Mr. Marriner was named a Commander of the Order of the British Empire in 1979 and knighted by Queen Elizabeth II in 1985.

His first marriage, to the cellist and noted antiquarian bookseller Diana Carbutt, ended in divorce. In 1957, he married Elizabeth Sims, known as Molly. She survives, along with two children from his first marriage, biographer Susie Harries and Andrew Marriner; three grandchildren; and a great-grandson.

A young Andrew Marriner showed remarkable promise on the clarinet, but his father declared that he would much rather see his son “lead a quiet life as a cricketer” than become a musician.

Andrew Marriner is now the first clarinetist in the London Symphony Orchestra.