Actor Tim Pigott-Smith has died at the age of 70, his agent has said.
Best known for his theatre work both in the West End and Broadway, he received an OBE for services to drama last month.
A statement from agent John Grant said: "It is with deep regret that I have to announce the sad news that Tim Pigott-Smith died this morning.
"Tim was one of the great actors of his generation. Much-loved and admired by his peers, he will be remembered by many as a gentleman and a true friend.
"He will be much missed. We ask that you respect the privacy of his wife, the actress Pamela Miles, his son Tom and the family."
Pigott-Smith had already filmed the forthcoming BBC2 drama King Charles III having successfully played the title role in the theatre production on Broadway and in the West End.
The play and TV drama depict Charles as monarch after the Queen's death as he refuses to sign a controversial bill into law.
It chronicles the political chaos that follows, leading to a constitutional crisis, rioting on the streets and a tank in front of Buckingham Palace.
The play won the Olivier Award and the Critics' Circle Theatre Award for best new play and was staged in London and New York, with Pigott-Smith winning rave reviews on both sides of the Atlantic.
He was nominated for both an Olivier and a Tony Award for his performance.
Pigott-Smith's memorable television and film roles have included Merrick, the racist police superintendent in the ITV mini-series The Jewel In The Crown, and parts in the movies The Remains Of The Day and Martin Scorsese's Gangs Of New York, as well as more recent appearances in Bond film Quantum Of Solace and Alice In Wonderland.
Pigott-Smith said the highlight of his career was The Jewel In The Crown, telling the Press Association in March: "That's the one that changed my life, a long time ago now, 1984, just in terms of a life experience and a job experience, quite phenomenal.
"It really was an international event, it went everywhere.''
He appeared opposite leading ladies like Dame Helen Mirren and led the theatre company Compass for a period.
He was due to star as Willy Loman in a revival of Arthur Miller's play Death Of A Salesman, which was scheduled to open at Royal & Derngate in Northampton on April 10, before an extensive nationwide tour.
His real-life wife Pamela Miles was expected to play Willy's wife Linda but pulled out of the production after breaking a bone during rehearsals and was replaced on the bill.
Born in Rugby, he trained at the Bristol Old Vic Theatre School and took smaller roles until his big break in The Jewel In The Crown.
His distinctive voice made him a popular narrator of documentary series and he lent his voice to Battlefield, a series which examined pivotal battles of the Second World War and the 2007 series Monarchy: The Royal Family at Work.
He had completed production on several films, including 6 Days, a drama about the hostage situation at the Iranian embassy in London in 1980, which also stars Jamie Bell and Mark Strong, and Stephen Frears's new film Victoria And Abdul, which also stars Olivia Williams, Michael Gambon and Judi Dench and is due for UK release in September.
He is survived by his wife and their son Tom.