Harry Kupfer, a German opera director whose inventive and often provocative stagings of Wagner masterpieces put him in the vanguard of a generation that sought to reinterpret the canon, died on Dec. 30 in Berlin. He was 84.

His death was announced by his agency, Arsis Artist Management. The agency did not specify the cause but said he had been ill for some time.

Mr. Kupfer, whose career began in East Germany, rose to international fame in 1978 with an innovative production of Wagner’s “Der Fliegende Holländer” at the Bayreuth Festival that reframed the story as the fantasy of its heroine. He became the director of the Komische Oper in East Berlin three years later and held that post for 21 years, through the reunification of Germany.

He developed a strong partnership with the conductor Daniel Barenboim, collaborating with him on a post-apocalyptic “Ring” at Bayreuth and later on Wagner’s 10 mature operas at the Berlin Staatsoper. Mr. Kupfer’s extensive work at two of Berlin’s three major opera houses led the German press to call him the “opera king of Berlin.”