Gloria von Thurn und Taxis wears her own Chanel dress and her own jewelry.

At the height of what she terms her “spoiled brat” period in the eighties, when no whim went ungratified, Princess Gloria von Thurn und Taxis, aka Princess TNT of Germany, went on the road with another kind of royalty: rock royalty.

“It was fabulous, because after Prince played a big venue, there was an after-hours show in some club,” she recalled recently and somewhat longingly. “So we would all go back to the hotel around midnight to change clothes and have dinner.” For Gloria, who was 27 when Sign “o” the Times was released, in 1987, that might have meant stepping into a Paco Rabanne chain mail minidress, her hair sculpted into a blue mohawk. “Around 3 in the morning, we’d then go out to a club where Prince would give another concert.”

Princess TNT’s appetites may be tamed today, or at least redirected, but during what some have called the Greed Decade, she reigned over the mosh pit of society figures who set the bar for excess: the Trumps, the Steinbergs, the Perelmans, the Gettys, the Thyssen-Bornemiszas, Marie-Hélène de Rothschild, the Kravises, Adnan Khashoggi. The list is long, catholic, intercontinental, and littered with pretenders.

If excess devolved into dissipation and even degeneracy, that was fine with von Thurn und Taxis, whose fearlessness and imagination were happily underwritten by her late, openly bisexual husband, Prince Johannes, whom she wed in 1980. (The Prince was 33 years his wife’s senior and was believed to be worth $3 billion at the time.) A world-class prankster, Johannes once, at a ball to which everyone was instructed to wear white, famously dribbled red wine on Princess Margaret’s seat while she was off dancing.

The Prince’s shenanigans seemed to license Princess TNT’s own. She does not think impersonating a dog on Late Night With David Letterman is anything to live down. Ditto her announcement on German television in 2001 that Africa has an AIDS problem because “blacks like to copulate.” Having thought it over for a number of years, Princess TNT reasoned that this epidemic could in fact be traced to the warm weather.

When she wasn’t putting her foot in her mouth, she was giving parties. Spending a million dollars at a birthday celebration may seem like peanuts, but in 1986 it earned her countless column inches. That year, Princess TNT hosted a three-day birthday party at her 500-room Bavarian castle for Johannes, featuring a cake decorated with marzipan penises, one for each of his 60 years. Garlands of bratwurst greeted the Maharaja of Baroda, the Erteguns, Mick Jagger, and throngs of other A-listers in the palace’s Hall of Muskets. At another event for that occasion, in New York’s East Village, poppers were handed out as favors.

Princess TNT was unstoppable at her zenith, but others found ways to stay in the game. In 1987, de Rothschild invited 450 guests to a fairy-tale ball for her debutante niece in Paris where ushers dressed as white rabbits, ballet dancers twirled in the background, and oeufs brouillés and spaghetti were served at 4 a.m. It was charming but, in light of what had gone down at TNT’s blowout, merely picturesque. Two years later, Gayfryd Steinberg held an Olympian bash on New York’s Long Island for her husband Saul’s 50th that included tableaux vivants enacting his favorite Old Masters—quaint, when you remembered the 5,000 loyal subjects in full Bavarian regalia who blew their tubas in a parade for Johannes’s 60th birthday.

The prince died in 1990, following two heart transplants just seven weeks apart, nailing the coffin shut, as it were, on the eighties and leaving the princess $576 million in debt, a result of her husband’s poor investments and a recessionary climate. When death duties were added to the arrears, the princess learned the meaning of austerity, giving up 24 of her 27 cars. She also refashioned herself as a businesswoman in pearls and wrist-length gloves, studying corporate law and managing the vast family holdings with a perspicacity even detractors admired.

Von Thurn und Taxis insists she would not do anything differently: “As Charles Aznavour sang, ‘Non! Rien de rien/Non! Je ne regrette rien.’ I think it’s the privilege of youth to be curious, fun-loving, even wild. I also think that every age has its own behavior. You don’t want to behave like you’re 70 when you’re in your 20s. And vice versa.”

In recent years, she has found God, leading her to become a major contributor to the Catholic church and an intimate of Pope Benedict XVI’s; she dines privately with His Holiness when she is in Rome, where she owns a “small” palazzo. (Von Thurn und Taxis also has homes in Manhattan, Paris, and Kenya.) Now that her children, Albert, Maria, and Elisabeth Theresia, are all adults, she has more time for collecting art and for personal projects, like penning an etiquette guide. Von Thurn und Taxis neither confirms nor denies that she and her co-author, Princess Alessandra Borghese, have become a couple, as many have speculated.

But oh, for the eighties. “The Gloria on horseback was just as happy as the Gloria all pimped up as a cowgirl in a ballroom,” von Thurn und Taxis says. “Still, I think I was always a multiple personality. Not in the pathological sense, of course.”

Hair and makeup by Arianna Campa for Chanel Beaute.