Peter Hall, a visionary theater director and impresario who founded the Royal Shakespeare Company and helped build Britain’s National Theatre into a producing powerhouse, has died. He was 86. He died Monday at a London hospital surrounded by his family, The National Theatre said Tuesday. He had been suffering from dementia.

Hall was one of the most influential figures in British theater since World War II. Richard Eyre, one of his successors at the National Theatre, said he “created the template of the modern director — part magus, part impresario, part celebrity.” —Associated Press