If stones could speak, the mosaic unveiled recently at an archaeological museum just south of Rome would have quite the tale to tell.

It was crafted in the first century for the deck of one of two spectacularly decorated ships on Lake Nemi that the emperor Caligula commissioned as floating palaces. Recovered from underwater wreckage in 1895, the mosaic was later lost for decades, only to reemerge several years ago as a coffee table in the living room of a New York City antiques dealer.

“If you look at it from an angle, you can still see traces of a ring from a cup bottom,” said Daniela De Angelis, director of the Museum of the Roman Ships in Nemi, referring to the piece’s modern use. The mosaic has been installed in the museum next to two other marble fragments salvaged from Caligula’s ships and was put on display Thursday.

“For us, it’s a great satisfaction today to see the mosaic in this museum,” said Maj. Paolo Salvatori of Italy’s elite art theft squad, whose investigations led to the mosaic’s return. “Bringing back cultural artifacts to their original context” is the ultimate goal of the squad, he said, and the recovery of the mosaic reflected cooperation among the squad, Italy’s cultural authorities and law enforcement in the United States.

Caligula’s rule only lasted from A.D. 37 to 41, but he enthusiastically embraced the trappings of the position, including an opulent residential compound on the Esquiline Hill in Rome, a villa on the southwest shore of Lake Nemi and the two ships.

“They were floating palaces,” whose “aquatic luxury” was likely inspired by a renowned barge used by Marc Antony and Cleopatra on the Nile, said Massimo Osanna, director general of Italy’s national museums.

Scholars are unsure whether the ships had a specific purpose, although some have posited that one was used for the worship of the Egyptian goddess Isis. In any case, Caligula did not skimp on the ships’ decor, which included mosaics on the walls, intricately inlaid marble floors, decorated fountains and marble columns. Bronze figures decorated the beams, headboards and other wooden parts.

If ancient sources are to be believed, Caligula was a deranged and despotic ruler with a voracious sexual appetite and a vicious streak of cruelty, but modern scholarship has thrown doubt on those accounts.

“There’s a lot of fake news about Caligula,” said Barry Stuart Strauss, a professor of history and classics at Cornell University. “I don’t want to make him out to be a nice guy or something,” he said, because Caligula executed a number of senators, had a sharp tongue and made many enemies. And when Caligula was assassinated in A.D. 41, “it wasn’t difficult to find people who wanted to assassinate him,” Strauss added. “But we can’t trust the myths.”

With Caligula’s death, the ships were destroyed and sank to the bottom of the lake. Various attempts to raise them over the centuries were unsuccessful as well as damaging, and the wrecks were repeatedly plundered, De Angelis said.

In 1895, antiquarian Eliseo Borghi managed to recover part of the ship’s decorative bounty, including some of the bronze decorations and parts of the marble floor. These items — including the recently returned mosaic, which he had restored using fragments of ancient marble integrated with modern pieces — were sold to museums in Italy and elsewhere in Europe as well as to private collectors.

VR Sunil Gohil