CARLISLE’S Roman bath house archaeology site has yielded yet more powerful evidence of its 'imperial' pedigree.

Experts at Newcastle University have confirmed that a lump of waxy pigment found at the Carlisle Cricket Club site is Tyrian purple, a rare dye reserved in Roman times for royalty or the super-wealthy.

It is the first time the substance has been found in Britain.

More valuable than gold, and made from the glands of Mediterranean sea snails, it was used by only the richest Roman citizens in decorative wall paints but only the emperor and his family were allowed to wear clothes dyed with it.

There is now mounting speculation that the Cricket Club site, which has produced numerous imperial artefacts, may have hosted a royal villa built for the Emperor Septimius Severus.

Born in Libya in 145, he was a ruthless politician and military leader, who served as emperor from 193 until 211. He came to Britain in 208 with 40,000 troops to conquer the “barbarians” north of Hadrian’s Wall.

Some experts believe that the scale of bath house structure uncovered at the Cricket Club site - believed to be the biggest Roman building on Hadrian’s Wall - also suggests a royal purpose. 

The discovery of Tyrian purple dye reinforces that claim.

The fist-sized lump of purple pigment, mixed with beeswax, was discovered during a community dig at the Cricket Club site in May last year as Professor Alice Roberts was visiting with a BBC Two Digging For Britain camera crew.

She marvelled at the finds, including imperial tiles, two huge carved heads, and hollow terracotta “vaulting tubes” of a design associated with North Africa. Professor Roberts described the site's archaeology as "absolutely mind blowing."

Speaking at the time, she spoke of “discoveries that have shocked the experts and revealed links to a Roman Emperor here in Britain.”

She said: “With this discovery of an imperial connection, it seems likely that this huge bath house was built for none other than Septimius Severus."

Wardell Armstrong archaeologist Frank Giecco, who has led the digs at the Cricket Club site, said: “Finding Tyrian purple at a site on the edge of the Roman Empire is incredible. 

“This dye was more valuable than gold and it was used only in the highest status buildings in the empire. The fact that it was left here is a story itself. Why was it left behind? It was so valuable.

“This is the first time it’s been found in Britain. It points to the highest status going. The only people who could wear purple had to be connected to the imperial court.

“As for Tyrian purple paint, anybody who had the money could use it, but in the Roman Empire it was the most expensive display of wealth imaginable. It's got to have something to do with this monumental building.”

The latest dig at the Cricket Club also uncovered ancient “intaglios,” carved gemstones of carnelian, jasper, and amethyst.

Experts say the vegetable glue used to set them into jewellery melted in the bathhouse saunas, leaving behind a treasure trove of valuable lost property that is only now being unearthed.News and Star:

Referring to the bath house, Frank said: “It’s Severin in date and we also have the North African vaulting tubes, and the IMP (imperial) tiles; and we know that there was school of gem cutters founded in Carlisle making this stuff.”

As well as the many quality finds, and a carved tribute to Severus’s wife, the Empress Julia Domna, the high status of the bath house building is indicated by its sheer size - at least 50 metres square and with two storeys.

It was equipped with a hypocaust, the Roman version of central heating.

During his military campaign, Septimius Severus may well have visited Carlisle – Luguvallium in Roman times – because nearby Stanwix was home to the only “double-strength” cavalry unit on  Hadrian’s Wall.

The fort's 1,000 cavalry troops had the job of patrolling and guarding the Empire's northern frontier. Frank added: “If Septimius Severus was here, this was effectively the centre of the Roman Empire at that time.”

Analysis of the Tyrian dye, extracted from sea snails, was done by Newcastle University archaeologist and lab technician Diana Blumberg (pictured below), who subjected a small sample of the pigment to “X-ray fluorescence analysis”.News and Star:

This revealed the presence of the element bromine, effectively confirming the link to a marine environment and the snails.

Explaining the Tyrian dye making process, she said: “Making this substance was a hugely laborious process, which we know about because Pliny the Elder [A Roman scholar] described the recipe for it.

“It’s estimated that approximately 10,000 snails went into making just 1g of the dye.”News and Star:

Reacting to the Tyrian purple find, Carlisle Cricket Club Chairman Mike Rayson said it reinforced his conviction that the Roman bath house was part of a "royal villa" for Septimius Severus and his family.

“The evidence is stacking up," said Mike. 

"We’ve had the North African vaulting tubes, the imperial IMP tiles, the tribute stone to Julia Domna, the huge bath house building, and now the Tyrian purple dye. I’d challenge anybody to prove Septimius Severus wasn’t living here.

“It’s better than Richard III being found in Leicester. This really does put us on the map for archaeology. We should forget the idea of Carlisle being the ‘Border City.’ This really was Emperor City.”

The latest community dig at the Carlisle Cricket Club site will be held between May 11 and June 15. To find out more, and get involved, go to the project’s website at this Uncovering Roman Carlisle link. 

The award-winning community archaeology project at the Cricket Club is being supported by Cumberland Council and other key partners.

Councillor Anne Quilter, the local authority’s Executive Member for Vibrant and Healthy Places described the latest finds as "exciting."

She said: "Following the discovery of the two Roman monumental heads and the other precious items, the project is unearthing some fascinating and globally significant finds. More digs are planned, as well as the opportunity to visit the site and see the ground breaking work underway.”

Read more: Carlisle Cricket Club yields yet more incredible Roman history

Carlisle Cricket Club archaeology facts

  • The site's archaeology began to emerge in 2017, when Carlisle Cricket Club officials commissioned Wardell Armstrong for a survey because they wanted to build a new pavilion on higher ground following a flood. The resulting finds were described as "Premier League" in their quality.
  • In several digs, supported by volunteers, there have been 2,800 "significant finds." They include around 550 Roman coins, 300 hair-pins, Imperial stamped tiles, glass beads, and a rare Roman doll’s foot, as well as cavalryman's tombstone, and 70 intaglios - carved gemstones, once set in the jewellery of wealthy Romans.
  • Hundreds of volunteers - many from overseas - have worked at site. The  next dig will be between Saturday May 11 and Saturday June 15. Tours will be held between 10am and 3pm each day. Schools are encouraged to visit - with over 600 pupils having visited in 2023.
  • The 2024 Uncovering Roman Carlisle project is funded by Cumberland Council, and the UK Government through the Shared Prosperity Fund, part of the Government's levelling up agenda.
  • The project was recognised by the Council of British Archaeology and the Marsh Charitable Trust as the Community Archaeology Project of the year 2021, with a member of the Project team Kevin Mounsey nominated for Community Archaeologist of the Year.
  • The episode of BBC Two's Digging for Britain episode featuring the Carlisle Cricket Club dig is available online. Go to this link.