Peter Hall and his first wife, actress Leslie Caron, in 1956. (AP/AP)

Peter Hall, an English-born theater director who fostered the work of playwrights including Samuel Beckett, Harold Pinter and Peter Shaffer, but who may be best known for reshaping the state of British theater by establishing repertory companies built largely on the work of Shakespeare, died Sept. 11 at a London hospital. He was 86.

The National Theatre of Great Britain, which Mr. Hall led for 15 years, announced his death. He had dementia.

Mr. Hall burst onto the British theater scene in 1955, directing the first English production of Beckett's landmark play "Waiting for Godot." While still in his 20s, he directed acclaimed actors such as Laurence Olivier, Peggy Ashcroft and Charles Laughton in Shakespearean plays in the Bard's home town of Stratford-upon-Avon.

At 29, Mr. Hall moved beyond the seasonal productions in Stratford to launch the year-round Royal Shakespeare Company in London, with a permanent group of actors performing classical and modern plays. Later, as managing director of the Royal National Theatre from 1973 to 1988 (succeeding Olivier), he advanced the notion that theater deserved government subsidies as a central pillar of the country's cultural identity.

In 1976, Newsweek theater critic Jack Kroll described Mr. Hall as "the most powerful cultural figure in a country whose culture is perhaps its only real remaining power."

Many of the world's finest actors appeared in Mr. Hall's productions, including Vanessa Redgrave, Peter O'Toole, Christopher Plummer, John Gielgud, Anthony Hopkins, Judi Dench and Dustin Hoffman, helping make London among the world's preeminent theatrical destinations.

Many playwrights on both sides of the Atlantic — from Tennessee Williams to Shaffer, who wrote "Equus" and "Amadeus" — sought to have their works performed under Mr. Hall's guidance.

"We all stand on the shoulders of giants," Rufus Norris, the current director of the National Theatre, told the Associated Press, "and Peter Hall's shoulders supported the entirety of British theater as we know it."

In addition to directing new plays, Mr. Hall also explored the classic repertoire, primarily the plays of Shakespeare. Throughout the 1950s and 1960s, it was not unusual for him to direct five to 10 plays a year, many of them simultaneously.

"You cannot call yourself an actor in this country unless you measure yourself against Shakespeare," he wrote in his 1993 autobiography, "Making an Exhibition of Myself." "The kind of classical company I wanted to form must be highly trained not only in Shakespeare and the speaking of his verse but also in modern drama — open to the present as well as expert in the past."

Peter Reginald Frederick Hall was born Nov. 22, 1930, in Bury Saint Edmunds, England. His father was a railroad stationmaster, and his maternal grandfather had been rat catcher on one of Queen Victoria's estates.

Mr. Hall described his mother as "hugely ambitious," and she encouraged his early interest in music and the arts. The family moved to Cambridge when he was about 10, and he often used his family's railroad discount to take the train to London to attend the theater.

By the time he was 14, he knew that he wanted to be a Shakespearean director. He received a scholarship to the University of Cambridge and, before graduating in 1953, he had acted in or directed more than 20 student plays. He moved to London and, while directing a small theater company, read "Waiting for Godot" during the slow summer season of 1955.

"I thought it was terribly funny and well written and had a marvelous rhythm to it," Mr. Hall told the Guardian newspaper in 2005. "But I didn't say to myself: 'This is the epoch-changing play of the midcentury.' I simply thought: 'What a wonderful thing to do in a slack August.' "

One early critic mocked "Godot" as "a play in which nothing happens, twice." But its theme of existential alienation, delivered by two down-and-out characters, caught the spirit of the age. The central characters, Vladi­mir and Estragon, wait for a person who never arrives, and their rambling, humorous conversation lends itself to wide-ranging political and philosophical interpretations. "Godot" has been continually revived over the years, including several times by Mr. Hall.

"I see my role as an interpreter," he said in 2005. "My job is to try to find out what the writer meant and then to try to find a means of conveying what he meant in terms that mean something to our audience."

In 1957, Mr. Hall directed the first London performances of Williams's "Camino Real," followed a year later by "Cat on a Hot Tin Roof." Mr. Hall also became closely identified with Pinter, premiering many of the playwright's bleak, despairing works, including "The Birthday Party" (1957), "Homecoming" (1965) and "No Man's Land" (1975).

Mr. Hall won his first Tony Award in 1967 for directing "Homecoming" — one of his 19 Broadway productions. He received his second Tony in 1981 for directing Shaffer's "Amadeus," about the rivalry between Wolfgang Amadeus Mozart and Viennese court composer Antonio Salieri.

Mr. Hall was not known for a signature directing style. Instead, his approach relied on a rigorous reading of the play itself, as if he were studying a musical score. He was a skilled pianist and directed more than 30 operas throughout his career and for six years was artistic director of Britain's Glyndebourne Festival Opera. In 1983, he directed Richard Wagner's "Ring" cycle in Bayreuth, Germany, on the 100th anniversary of Wagner's death.

Some of his efforts in opera courted controversy or were critical disasters. A 1982 production of Verdi's "Macbeth" at the Metropolitan Opera was derided for its over-the-top effects, including witches riding on brooms. In 1986, he had his wife at the time, singer Maria Ewing, completely disrobe while performing the "Dance of the Seven Veils" in Richard Strauss's "Salome."

Among the books Mr. Hall wrote was "Shakespeare's Advice to the Players" (2003), which explored how actors should immerse themselves in the rhythm of Shakespeare's oceanic flow of words, as if they were athletes in training.

"Shakespeare gives you the clues. He tells the actor when to go slow, when to go fast, when to pause, which word to accent," Mr. Hall told the Los Angeles Times in 1999, while directing three of the Bard's plays in Los Angeles.

"The modern actor's habit is to attack the beginning of the line and fade on the end. But what Shakespeare wants to tell the audience is usually in the second half. It's why he loves rhyme."

In 1956, he was directing a British stage production of "Gigi," based on a novella by Colette, starring French-born movie star Leslie Caron. They married that year and had two children. Caron later wrote that she was drawn to Mr. Hall's charisma and ambition, but the marriage grew strained by his bouts of severe depression and his demands that she give up her career. The marriage ended in divorce, cemented by her affair with Warren Beatty.

Mr. Hall's next two marriages, to Jacqueline Taylor and Ewing, also ended in divorce.

Survivors include his wife since 1990, Nicki Frei, a former press officer for the National Theater; two children from his first marriage, Christopher Hall and Jennifer Hall; two children from his second marriage, theatrical director Edward Hall and Lucy Hall; a daughter from his third marriage, actress Rebecca Hall; a daughter from his fourth marriage, Emma Hall; and nine grandchildren.

Mr. Hall directed several films, including a 1995 crime thriller "Never Talk to Strangers" with Rebecca De Mornay, and "Akenfield" (1974), about life in a rural British village. He received a knighthood in 1977.

After leaving the National Theatre in 1988, Mr. Hall launched his own theatrical group, the Peter Hall Company, and continued to direct occasional plays for the Royal Shakespeare Theatre and other stages.

His final production came in 2011, with Shakespeare's "Twelfth Night" at the National Theatre, with his daughter Rebecca in the starring role of Viola.

"I'm at my absolute happiest in the rehearsal room," Mr. Hall said in 2010. "There is nothing else like it. With every production there's at least one day when everyone is better than they really are, all at once, and that moment is like a cake rising, and that's really what I do it for."