Venice lagoon reveals grim secrets

San Lazaretto Nuovo served as a quarantine outpost

Brian Barron reports on a modern-day investigation into one of the most horrific episodes in Venice's history

This week, in their regatta, Venetians are paying homage to their ancestors who founded La Serenissima, the Most Serene Republic - today a prime tourist destination.

But just 15 minutes away across the lagoon, a darker chapter in Venice's glittering history is being revealed.

The Venetian authorities are surveying two ancient ships found beside the lost island of San Marco in Boccalama that disappeared beneath the rising lagoon over 500 years ago.

The medical world of that period didn't know what to do. So the policy was to isolate victims, their relatives and all visitors.

Dr Nelli-Elena Vanzan Marchini, plague expert

The island - the site of an abandoned 11th century monastery - became a mass grave for scores of thousands of victims of the plague, the Black Death, in 1348.

Now, on what was the foreshore, they're unearthing the two oldest ships ever found in Venice - sunk by the island's monks in a doomed attempt to bolster sea defences against the encroaching lagoon.

Tracking the plague's path

On the lost island of San Marco, a ship is being uncovered that was built 700 years ago. The second ship, a 13th century galley, is now only a few inches below the water.

Aided by the new discoveries, historians are tracking the path of the plague.

Near the lost island is another abandoned monastery, San Lazaretto Nuovo.

This was Venice's quarantine outpost during the 500 years of recurring plague - a haunted place where incoming crews and passengers were detained in the hope of checking the Black Death.

One of the oldest ships ever found in Venice emerges from the mud

But no one knew then it was carried by fleas from black rats on the ships themselves.

"When the plague came, Venice slipped into desperation," says Dr Nelli-Elena Vanzan Marchini, a plague expert.

"The medical world of that period didn't know what to do. So the policy was to isolate victims, their relatives and all visitors. But eventually these small islands were overwhelmed by the sheer numbers."

Excavation deadline

At the end of this month, part of a steel barrier will be lowered and the lagoon waters will once again cover the lost island.

Incoming crews were detained here in the hope of halting the plague

That is thought to be the best way of preserving the vessels until, at a future date, they can be salvaged and brought to a museum.

The deadline for the operation is determined partly by the money available, says Marco D'Agostino, chief archaeologist.

"Old, wet wood deteriorates when exposed to air and sunlight. So this is the survey stage - especially for scientific and photographic analysis."

But in Venice's naval museum there is disquiet at the authority's decision to leave the ancient wrecks where they are for the moment.

Gilberto Penzo, a naval historian believes the decision is "completely crazy".

"I am sure if you leave the boats there they survive for only six months because the lagoon is very dangerous for old waterlogged wood."