Italian divers are to mount an expedition this week to try to find the long-lost remains of a ceremonial barge built on the orders of the Emperor Caligula 2,000 years ago.
Caligula, renowned as one of Rome’s most psychopathic and sadistic rulers, had enormous boats built so that he could take pleasure cruises on Lake Nemi, situated in a range of volcanic hills 20 miles outside Rome.
The remains of two such barges were found between 1928 and 1932 when the lake was partially drained on the orders of Fascist dictator Benito Mussolini, who had heard of the legend of the lost boats.
An ancient Roman underground tunnel that connected the lake to surrounding farmland was re-opened in order to allow the water to drain out, revealing the skeletons of the two boats and a treasure trove of artefacts.
It is believed there may have been a third boat, which has never been found.
We know from documents from the 15th century that one of the boats went down in an area of the lake different to where the other two were found during the Fascist era
Specialist divers from the Civil Protection Agency, which normally responds to disasters such as earthquakes, floods and avalanches, and from the paramilitary Carabinieri police force, will start exploring the 100ft-deep lake on Wednesday.
They will use sonar and other advanced equipment to scour the muddy depths in the hope of finding the remains of the fabled third ship.
They are working in part on information provided by local fishermen, who say that in one area of the lake their nets often get snagged and they haul up Roman artefacts.
“We know from documents from the 15th century that one of the boats went down in an area of the lake different to where the other two were found during the Fascist era,” said Alberto Bertucci, the local mayor.
It is not known how the huge wooden boats ended up on the bottom of the lake.
It may have been that they simply deteriorated over time and became waterlogged, or that Caligula’s successor, Emperor Claudius, had them sunk deliberately in an attempt to expunge some of the excesses of Caligula’s reign.
They were essentially floating palaces, decorated with gold, marble and mosaic floors and boasting luxurious facilities such as heating and plumbing.
They were said to have been equipped with sails made of purple silk and had richly-decorated prows.
The onboard entertainment may even have extended to orgies.
After being recovered in the 1930s they were kept in a museum, but it was almost completely destroyed in May 1944 during fighting between the Allies and German forces.
A few charred timbers and some bronze figures were all that survived the blaze.
Scale model replicas were created in the 1950s, which can be seen today in a rebuilt museum on the shores of the lake.
They are just one-fifth the size of the originals, the largest of which was 240ft long.
Caligula reigned from 37AD to 41AD and is depicted by historians as a depraved megalomaniac.
His short rule came to a bloody end when he was assassinated by officers of the Praetorian Guard, amid a revolt over his sadistic behaviour and reckless spending.
Scholars have debated for years whether the barges were built purely as pleasure craft, or whether they were constructed as floating temples in honour of the goddess Diana or other popular deities.
It has been suggested that Caligula ordered them built as a form of one-up-manship, in order to rival ceremonial barges constructed by the Ptolemaic rulers of Egypt.
Born Gaius Caesar Germanicus, as a child he began accompanying his father on military campaigns.
He wore a miniature uniform and boots, earning him the nickname “Caligula”, Latin for "little boots."
The name stuck with him for the rest of his life.
His reign was marked by increasingly eccentric behaviour. He often dressed as a woman, and declared himself to be a living god.