When stains had to be cleaned from a mosaic that once decorated a lavish pleasure vessel from the first century, they were not remnants from the debauched revelries that the murderous and sex-crazed Roman Emperor Caligula used to hold on the ship.

Instead, they were vestiges of modern, everyday life from a New York City apartment almost 2,000 years later. But exactly how the mosaic ended up as a coffee table in a Park Avenue living room is still something of a mystery. 

The mosaic is a four-and-a-half square-foot geometric piece made up of rich green and white marble and purple-red porphyry, a type of rock textured with crystals that was frequently the choice of Roman emperors. It had been part of an inlaid floor in one of the gigantic and extravagant party ships commissioned by the emperor Caligula, a much-despised ruler whom history has described as cruel, depraved — and maybe even a little deranged. 

When Caligula was assassinated in A.D. 41 after ruling for only four years, his two ships were sunk where they sat, in the middle of Lake Nemi, a small volcanic lake southeast of Rome. 

Over the ensuing centuries, several attempts had been made to raise the opulent ships from the lake. Italian Renaissance architect Leon Battista Alberti first attempted to salvage remnants in the mid-15th century but was ultimately unsuccessful. Then in 1895, divers conducted a thorough survey of the site and began resurfacing relics from the lake's mud floor. That is when archaeologists unearthed certain colorful stone mosaic tile. 

"The deck must have been a marvelous sight to behold, and it goes beyond the power of imagination for its strength and elegance…" Italian archaeologist Rodolfo Lanciani wrote of the discovery in an issue of The Youth's Companion, according to an 1898 article in The New York Times. "Last of all comes the pavement trodden by imperial feet, made of disks of porphyry and serpentine, not thicker than a silver dollar, framed in in segments and lines of enamel, white and gold, white and red, or white, red, and green. The colors are perfectly brilliant. Fancy the deck of a modern yacht inlayed in enamel."

Stretching 230 feet and 240 feet long and mostly flat, the wood ships were clearly constructed as barges meant to sit in placid water, not to negotiate waves. According to The New York Times in 1908, the ships were topped with silk sails and featured orchards, vineyards, and even bathrooms with running water ("quite unnecessary when one can so easily jump overboard," the Times offered). To be certain whose ship bore such luxurious accommodations, the lead pipes were inscribed Gaius Caesar Augustus Germanicus, Caligula's official name, according to a 1906 issue of Scientific American. 

It would not be until the twentieth century that the ships' full grandeur was revealed. Fascist dictator Benito Mussolini was so taken by Caligula — whose legend includes turning his palace into a brothel and appointing his horse as a high-ranking senator — that he ordered Lake Nemi be partially drained so the two ships could be raised. In the early 1930s, Mussolini commissioned a museum next to the lake to house the ships and their treasures once they were recovered.  

But after sitting submerged for nearly 1,900 years, Caligula's floating dens of debauchery would not see dry land for long. During World War II, Nazis used the museum as a bomb shelter, and the Italians of Nemi allege the retreating Germans set fire to the building in 1944, destroying most objects inside. 

Destined to hold idling beverages on Manhattan's Upper East Side, the colorful mosaic floor tile bears no evidence of this fire damage. Dario Del Bufalo, an Italian expert on ancient marble and stone, told 60 Minutes correspondent Anderson Cooper this suggests the mosaic had either been snuck out of the museum before the fire or had been in private hands since Mussolini had it extracted from the lake in the 1930s.

At some point after World War II, the mosaic disappeared. Del Bufalo included a photo of it in a book on porphyry he published in 2013, and during a lecture and book signing at the Bulgari jewelry store on Manhattan's 5th Avenue, he overheard a remarkable conversation. 

"There was a lady with a young guy with a strange hat that came to the table," Del Bufalo said. "And he told her, 'What a beautiful book. Oh, Helen, look, that's your mosaic.' And she said, 'Yeah, that's my mosaic.'" 

Shocked by the statement as much for its substance as its nonchalance, Del Bufalo quickly wrapped up signing books and sought out the pair. He found the young man who told him that yes, this is Helen's coffee table at her home on Park Avenue.  

The Helen in question is Helen Fioratti, an art dealer who owns a gallery for European antiques and lives in Manhattan. She told The New York Times in 2017 that she and her husband, Nereo Fioratti, a journalist, had bought the piece in good faith from an Italian noble family in the 1960s and had no reason to suspect they were not the mosaic's rightful owners. Once the Fiorattis brought the mosaic home to their Park Avenue apartment, they affixed it to a base to turn it into coffee table. 

"It was an innocent purchase," Fioratti told the Times in 2017. "It was our favorite thing, and we had it for 45 years."

But prosecutors for the Manhattan district attorney's office say evidence suggests the mosaic had been stolen from the Nemi museum, also according to The New York Times. In September 2017, they seized the mosaic and returned it to the Italian government. 

60 Minutes' request for comment from Fioratti went unreturned.

Del Bufalo told 60 Minutes he sympathizes with Fioratti. "I felt very sorry for her, but I couldn't do anything different, knowing that my museum in Nemi is missing the best part that went through the centuries, through the war, through a fire, and then through an Italian art dealer, and finally could go back to the museum," he said. "That's the only thing I felt I should have done."

After receiving a thorough cleaning to remove all traces of its former life as host to coffee, tea, and the occasional flower vase, the mosaic was unveiled on display at Nemi's Museum of the Roman Ships in 2021.

In the meantime, Del Bufalo, had fashioned a convincing replica of the mosaic. He told 60 Minutes he wants to make a copy for Fioratti to return to her apartment on Park Avenue, because as he explained, "I think my soul would feel a little better."

The video above was originally published on Nov. 21, 2021 and was produced by Andy Court, Brit McCandless Farmer, and Will Croxton. It was edited by Will Croxton.