His great-grandfather, Kaiser Wilhelm II, unleashed Germany's armies and helped plunge Europe into World War I, but Prince Ludwig Rudolph of Hanover caused nary a ripple on the tides of history. Nor had he ever intended to. Ludwig, 33, and his 26-year-old bride, former fashion model Countess Isabelle von Thurn-Valsassina, didn't want to work their will on the world; they didn't want to work at all. His family's wealth, based on immense ancestral landholdings, probably exceeded $200 million. Ludwig and Isabelle wanted only to have fun, fun and more fun, until long after it wasn't fun anymore.

When the princely couple were laid to rest Dec. 2, among the 500 mourners who gathered in a freezing rain in the village of Grünau in Upper Austria were the Archduchess Regina of Hapsburg and three other members of that deposed imperial family. Ludwig's pedigree had placed him in line, albeit distantly, for the British throne. But many of Europe's younger elite stayed away and sent funeral wreaths signed only with their first names or initials. The eulogy was similarly discreet, making no mention of the causes of death: drugs and suicide.

Remaindered royalty whose only realm was Europe's demimonde of bored discocrats, the prince and princess had met self-inflicted ends, she with drugs in her veins, he with a rifle barrel in his mouth. Only 13 months before, they had celebrated their wedding with a lavish five-day rock and roll fete at the Alpine castle of Bleiburg in southern Austria, home of the bride's family. Isabelle had danced until she collapsed. Five months later, she bore Ludwig a son, Otto.

Recently, the prince had outfitted Königin Villa, his family's magnificent summer residence in Gmunden overlooking Lake Traun in mountainous northwest Austria, with a high-tech recording studio. (The couple also maintained pieds-à-terre in Vienna and Munich and occupied a full wing of the 160-room Marienburg palace in Hanover city.) Ludwig planned to launch a career as a rock producer. "He was cheerful, very optimistic about his future," said the couple's friend Wilhelm Maurer, owner of an exclusive sporting-wear shop in Gmunden.

But the needle marks that pathologist Johann Haberl reported finding on the arms of the prince and the princess bespoke a less than cheerful life: The royal couple had king-size drug problems. At the time they became engaged, in fact, friends had commented, "Now the hash princess has found her hash prince." Both Isabelle and Ludwig were known to run with West Germany's Schickeria, "chic crowd," the "high" society of rock musicians, investment bankers, expensive call girls and bored blue bloods among whom use of cocaine is fashionable. Seven years ago, police came across a $4,000 check, bearing Ludwig's signature, made out to a suspected drug dealer. Ludwig's lawyer argued that the money was for the purchase of a car, and the prince escaped conviction. That same year he was called as a witness in an investigation of movie producer Rainer Werner Fassbinder's drug ties. Then in 1987, according to the West German newspapers, police turned up a $20,000 check, this one signed by Isabelle, made out to another suspected drug dealer. And only a week before Ludwig's death, police had abandoned yet another investigation into the prince's drug connections, having once more run up against a wall of silence among the prince's titled friends. Said Salzburg narcotics detective Karl Walder: "There are barriers we simply cannot cross."

A host of those for whom such barriers do not exist, including Arthur John, the musical arranger for Michael Jackson, and the members of Diepop, a West German band Ludwig planned to record, turned out at Konigin Villa on the night of Nov. 28 to celebrate the prince's 33rd birthday. Around midnight Isabelle retired to the upstairs bedroom she shared with her husband, and at about 2:45 A.M. Ludwig followed her. He found her, dressed in jeans and a black sweater, prostrate on the bed. Ludwig and some of the guests tried for an hour to revive her with mouth-to-mouth resuscitation and heart massage before calling an ambulance. Isabelle was pronounced dead at the scene, the cause later attributed to heart and lung edema due to an overdose of cocaine. Police found small amounts of cocaine and heroin, as well as syringes, in her night table.

In the confusion after the police arrived, Ludwig and his blue Mercedes 300 SE coupe were discovered missing, and a search was begun. Police finally located the prince just after dawn, when a forester found his car parked, with the engine still running, in a grove of snow-covered fir trees 15 miles from the villa, near the Hanover family hunting lodge. Behind the wheel, the muzzle of his hunting rifle still in his mouth, lay the lifeless Ludwig. It was discovered later that, just before he drove off, the prince had called his older brother, businessman Ernst August, in London, telling him of Isabelle's death and his suicide plans. He had asked Ernst to take care of their baby. Explaining that police planned no further investigation, an official in the state prosecutor's office offered a perfunctory epitaph for the prince and his princess. "Death," he pronounced, "ends all punishment."

—Montgomery Brower, and Franz Spelman in Munich