Colin Davis, the British conductor who guided some of the world’s leading orchestras in often-revelatory performances of Mozart, Berlioz, Sibelius, Britten and Tippett, died April 14 in London. He was 85.

The London Symphony Orchestra, where he was principal conductor for 11 years before stepping down in 2006, announced the death but did not disclose the cause. For the last seven years, he was LSO president — a title previously held by only four other conductors, including Leonard Bernstein.

His career included stints as head of the Royal Opera House in London’s Covent Garden, the Bavarian Radio Symphony Orchestra, the Dresden Staatskapelle, the BBC Symphony Orchestra, and Sadler’s Wells opera in London.

But he retained a particular link with the LSO, which during his association — his principal conductor tenure was preceded by 20 years as principal guest conductor — rose to become the marquee orchestra in London. The association remained vivid in the minds of Americans who saw him lead the orchestra in annual appearances in New York, and sometimes other cities (they came to Washington in 2001) as well.

As a conductor, he did particularly memorable work as a Mozartean, even though he had no use for period instruments and the so-called historically informed performance movement. He was able, the pianist Mitsuko Uchida once told the London Guardian, “to unlock the pure joy that is contained within the music.”

The President of the London Symphony Orchestra Sir Colin Davis, performing here in 1965, has died at the age of 85. (Erich Auerbach/Getty Images)

Perhaps it was no accident that he had a special knack for Berlioz the maverick. In his later life, he projected the image of a serene and intellectual elder statesman, what with his knitting, pipe-smoking and voracious reading habit. But he was considerably more volatile, and more of an outsider, in his youth.

Passionate and mercurial, he alienated some musicians and failed to establish the kinds of working relationships he wanted with his own country’s leading institutions. He had what he described as a crisis in the mid-1960s that led not only to a career implosion, but also to the destruction of his first marriage, to the soprano April Cantelo, when he fell in love with their two children’s Iranian au pair, Ashraf Naini, known as Shamsi. They were married in 1965 and had five children before her death in 2010.

Still, that marriage did not entirely end the ups and downs of his career, particularly during his tenure at the Royal Opera House, which saw some brilliant successes (including a seminal recording of Britten’s “Peter Grimes” with Jon Vickers) and some ostensible fiascoes.

Even after he stepped down from Covent Garden and was without a fixed artistic home in Great Britain, he never gave up his London address. Nor did he yield to the entreaties of some of the leading orchestras in the United States, including those in Cleveland, Boston and New York (where he was for a time principal guest conductor). Instead, he took the posts in Munich and Dresden, cultivating a new interest in the German repertory.

There is no question that the LSO post represented something of a coming home.

Colin Rex Davis was born Sept. 25, 1927, one of seven children of a bank clerk, Reginald Davis, and his wife, Lillian. Both parents loved music and played it at home, but when he started out on an instrument, it was not piano, but clarinet.

He never quite mastered the piano, eyeing it with a certain amount of mistrust. Instead, the clarinet led him from his school band to the Royal College of Music to the Household Cavalry band, immediately after World War II, in fulfillment of his military service requirements.

He then began teaching himself to conduct in earnest, picking up work with a range of small ensembles when he wasn’t practicing conducting recordings in the privacy of his home and playing clarinet on the side — including one stint in the Glyndebourne Orchestra.

His ascent was fairly quick. In 1957, he was named an assistant conductor of the BBC Scottish Orchestra; in 1959, he began conducting with Sadler’s Wells.

There followed two iterations of the classic musical rags-to-riches story: He was called on to jump in at short notice for two major stars, Otto Klemperer (in a high-profile concert performance of “Don Giovanni” with Elisabeth Schwarzkopf and Joan Sutherland at the Royal Festival Hall) and Sir Thomas Beecham (in “The Magic Flute” at Glyndebourne). Mr. Davis mastered both assignments, placed himself squarely on the map, and became music director of Sadler’s Wells shortly thereafter, a post he held until 1965.

He took over at Covent Garden in 1970, succeeding Sir Georg Solti and turning down an offer from the Boston Symphony Orchestra on the grounds that his own opera house needed him. His 15-year tenure saw some triumphs, including Berlioz’s “Les Troyens” and “Benvenuto Cellini,” and some struggles, including a “Nabucco” (Verdi) that was booed.

He was criticized by some for leaving the standard repertory to other conductors, though he did lead a “Ring” (met with mixed reviews) that brought him to Bayreuth, as well as a number of important contemporary works by Sir Michael Tippett and others.

It was during his later years, particularly with the LSO, that some critics’ early assessments of him as a hot-headed firebrand — “A conductor of powerful enthusiasms rather than steady all-round excellence,” Andrew Porter wrote in the 1980 edition of the New Grove Dictionary of Music — finally evolved into an appreciation of what those enthusiasms had yielded. Handsome, craggy-faced, unfailingly polite and unconventionally thoughtful, he became not only respected, but widely beloved — in part because he considered it the conductor’s responsibility to get out of the way and let the music happen.

“The goal of making music is freedom to cooperate,” he said to the Telegraph in 2008. “It’s a sensitive, delicate business. It depends on mutual respect. If your ideas come from and belong to the music, the musicians will be interested in the same things, so there will be no conflict. The whole point of having a conductor is to stop people talking, otherwise it’s chaos.”