Although he later gained his highest profile in film and television work such as "House of Cards" (1990), Richardson was primarily a classical stage actor. His first engagement after training was with Birmingham Repertory Theatre, where his performance of "Hamlet" led to an offer of a place with the RSC. He was a versatile member of the company for more than 15 years, playing villainy, comedy and tragedy to equal effect. He was The Herald in Peter Brook's production of "Marat/Sade" in London in 1964; in the New York City transfer he took the lead role of Jean-Paul Marat (and so became the first actor to appear nude on the Broadway stage), a performance he repeated for the 1967 film "Marat/Sade".