Actor Ian Richardson, who brought Shakespearean depth to his portrayal of a thoroughly immoral politician in the British television drama House of Cards, died Friday at age 72, his agent said.

Richardson died at his London home "in the early hours this morning in his sleep. He hadn't been ill or anything," said agent Jean Diamond.

British actor Ian Richardson, seen here in London in 2006, was best known for the TV drama House of Cards. British actor Ian Richardson, seen here in London in 2006, was best known for the TV drama House of Cards.
(Dave Hogan/Getty)

He played the silkily evil Francis Urquhart in three British miniseries, House of Cards in 1990, To Play the King in 1993 and The Final Cut in 1995.

Urquhart's smooth riposte to any slur against another character — "You may think that; I couldn't possibly comment" — was picked up by British politicians and heard again and again in the House of Commons.

House of Cards was brilliantly, if accidentally, timed. It appeared in Britain in the same year that Prime Minister Margaret Thatcher was brought down by feuding in her Conservative Party.

"What that role did was to turn me from a jobbing actor that the cognoscenti were aware of into a star that the country's entire viewing population knew," Richardson said in an interview last year with the Daily Mail.

"Urquhart was a wicked character but Richardson portrayed him in such a way that everybody loved it. In anybody else's hands, that role could have fallen flat on his face," said Michael Dobbs, who wrote the book on which it was based.

In the feverish atmosphere of Thatcher's downfall, "even John Major's leadership campaign in 1990 came to a halt at 9 p.m. on a Sunday night so that the whole campaign team could sit down and see what was happening," Dobbs said.

Richardson, born in Edinburgh in 1934, joined the Royal Shakespeare Company in 1960.

On Broadway, he played Jean-Paul Marat in Marat/Sade in 1965, reprising the role in the United Artists film the following year, and Henry Higgins in a 1976 revival of My Fair Lady.

Other television roles included Bill Haydon in John Le Carré's Tinker, Tailor, Soldier, Spy, Sir Godber Evans in Porterhouse Blue and Sherlock Holmes in The Hound of the Baskervilles.

He is survived by his wife, Maroussia, and two sons.