Corin Redgrave, a versatile actor and ardent left-wing political activist who, as the son of Michael Redgrave and the brother of Vanessa and Lynn Redgrave, was the prince of the royal family of English theater, died on Tuesday in London. He was 70.

His death was announced by his wife, Kika Markham, The Associated Press reported. No cause was given. He had survived a heart attack in 2005.

Redgrave was a less celebrated performer than his father, who was known for his Shakespearean eloquence, matinee idol good looks and turbulent personal life; or his sisters, who became internationally recognized figures, as glamorous as they were accomplished. But he was a forceful, impassioned actor who became a veteran of the British stage, both in comedies and tragedies, and was especially at home in enduring works by Shakespeare, Chekhov, Noel Coward and Harold Pinter.

Redgrave devoted as much energy to political causes as he did to acting. He had close ties with far left organizations.