One of the world's most celebrated opera directors, Germany's Harry Kupfer, has died at the age of 84 in Berlin, his agency confirmed on Tuesday. In a career spanning 44 years, Kupfer worked at opera houses across Germany and was chief director of Berlin's iconic Komische Oper for more than two decades. Born in 1935, Kupfer studied in Leipzig and first worked in then-communist East Germany. But he rose to fame in 1978 with a production of Richard Wagner's "The Flying Dutchman" at the world-renowned Bayreuth festival. He took the reins at the Komische Oper three years later in 1981. A student of Komische Oper founder Walter Felsenstein, Kupfer staged works by Mozart and Wagner and oversaw two world premieres at the opera house before bowing out in 2002. He returned to Bayreuth in 1988, staging Wagner's "Ring of the Nibelung" alongside Argentine-Israeli conductor Daniel Barenboim. After the fall of the Berlin Wall, Kupfer cooperated with Barenboim again on an ambitious project to stage one Wagner opera a year over the course of a decade at the Berlin State Opera. He continued to work until right up to his death, directing around the world and staging Georg Friederich Handel's Poro in a triumphant return to the Komische Oper earlier this year.