SIX centuries ago on a midsummer’s day, a little ship docked at the Dorset port of Melcombe Regis.

Today the place is known as Weymouth and while the nature of the vessel’s legitimate cargo has been lost in time, we now know it was also carrying the Black Death, the deadly plague that had wiped out more than a third of the population of Europe and would go on to do the same in Britain.

Even as the men of Melcombe worked, they were becoming infected with the lethal Yersina-Pestis bacterium, spread on the fleas of the black rats which infested the ships.

As the fleas bit the workers they were transferring the bacteria into their blood stream from where, within a matter of hours, it would travel through their lymphatic system causing giant, apple-sized swellings known as ‘buboes’: the bubonic plague.

Then the bacterium would start its lethal assault on the spleen and lungs and they would be dead within four days.

Lulworth, Bridport and Wareham were laid waste within three months, as was Portland, where so many people died that the quarries fell silent and King Edward III issued an order restricting movement off the Isle.

The nightmarish scenes of bodies piled high on carts and tipped into plague pits seems like a vision from another planet.

But, say scientists, the plague is very much with us. Strains of the disease still cause 2,000 deaths a year but in spite of that, thanks to some amazing new discoveries, they hope it may even have a role to play in modern medicine.

Researchers using DNA from 53 bones and 46 teeth of victims exhumed from a plague pit under the Royal Mint in London show the infection actually evolved from a harmless soil bacteria.

And using this knowledge they believe they can enter ‘a new era of research into infectious diseases’.

How? Well, according to leading geneticist Hendrik Poinar, who was part of the team which reconstructed the Black Death genome: “In 660 years of evolution as a human pathogen there have been few changes in the genome of the ancient organism.

“Those changes may or may not account for the increased virulence of the bug that ravaged Europe,” he says. “The next step is to determine why this was so deadly.”

The researchers’ findings, published this week in the respected scientific journal, Nature, are part of our on-going fascination with this disease and the horror it wrought.

Films such as Contagion, starring Jude Law and Kate Winslet show us how we might react to such a threat now.

But in the medieval era the ignorance about disease was breathtaking.

It was a time before the notion of circulation was understood, leading to horrific ‘cures’.

Physicians would either bleed the patient dry or pierce the buboes with the feather of pigeon and, if that didn’t work, the physician would split the breast of the pigeon and hold it – dead or alive – onto the buboe to draw the pestilence from the body.

Many believed the disease was God’s wrath – even though the evidence showed that the clergy, with their propensity for travelling round, were far more likely to be victims.

The parish of West Chickerell lost its priest and within a few months his successor had gone too but this didn’t stop the faithful from turning nasty.

Bishops, monks and clergy came under physical attack, possibly in part due to the failure of the church’s standard advice, that prayer and penitence would conquer death.

So, given that the plague is still with us and isn’t so very different to the one that wiped half of Europe off the map, should we be afraid?

Not really. According to the World Heath Organisation it can be treated with common antibiotics such as streptomycin and tetracycline.

And, if the research team has its way, the Black Death may even one day be helping us.