NEARLY 2,000 years ago, York was the most important place in the western hemisphere. The Roman Emperor had taken up residence and thousands of social climbers from all corners of the empire flocked to the city to be part of the scene.

The man attracting all the fuss was Septimius Severus, the first black citizen to hold Rome’s highest office. For the final three years of his reign, he made York his home and brought to the city a cosmopolitan period of culture, fashion and importance that has not been matched since.

Before Severus arrived, most residents had not seen anyone from the next province, never mind Syria or Mesopotamia; yet almost overnight, their city was filled with every known nationality.

The emperor’s striking looks, tight curly hair and straggly beard were said to have wowed everyone. Severus was also a dab hand at promoting his wife, Julia Domna, and while most in York had seen their faces on coins, now they were here in person – and everyone wanted to look like them.

Here quite possibly was the birth of celebrity culture, but the greasy lank hair of the Brigantes and Celts was never going match the golden couple’s locks. Alert to the new fashion, however, hairdressers came up with ingenious products, including curlers made from jet.

Friday is the 1800th anniversary of the death of Severus and to celebrate his influence on the city, the Yorkshire Museum is holding an exhibition throughout the month which uses objects and stories from his time as an inspiration for contemporary projects.

Among the events are performances by the Theatre Royal Young Actors and a fashion display by students from York College based on their interpretation of what Severus and Julia Domna might wear today.

The exhibition is in partnership with the Museum’s Precious Cargo Project which is led by Aisha Ali-Sutcliffe.

“When Severus arrived he made a real impact,” she says. “He didn’t look like a traditional Roman Emperor and with his glamorous wife they were a unique couple; York’s first celebrities really, it was a bit like Posh and Becks turning up.

“It was an exciting time. Severus and Julia Domna were style icons who with their huge entourage influenced fashion and culture in the city.

“There were also many different languages being spoken and people began to change their diet because spices and a different way of cooking came over from Africa. Third century York was a very cultured city.”

On February 21, young black authors from Leeds will explore African history and Severus’s life through music, theatre and performance. Aisha says they have drawn deep inspiration from the emperor.

Many of them were surprised to learn that while Barak Obama made history by becoming America’s first black president, two millennia before he took office, the Romans were already leading the way for a more tolerant approach.

Severus belonged to a class of Romanised Africans in what is now Libya. Although his mother was of Italian Roman extract, his father was Punic – a genetic mix of the Phoenicians and Berbers – and an obscure provincial with little or no standing in Rome.

Severus had ambitions from an early age, but he was held back through a lack of connections. However, two cousins, who both served as consuls, fixed it for him to enter the Roman senate where he gained the favour of emperor Marcus Aurelius.

Life as a senator was mainly spent overseas, before Severus became a magistrate. Later he joined the army and became an accomplished general who, having defeated his enemies in a series of civil wars, went on to victories across the empire.

His time came in 193 AD when Pertinax was murdered. Troops loyal to Severus proclaimed him Emperor and he rushed back to Italy. As he arrived, the former Emperor, Didius Julianus, had been condemned to death by the Senate and Severus took Rome without opposition.

But another challenger soon emerged in Clodius Albinus, who was hailed emperor by his own troops. After a short stay in Rome, Severus decided to remove his rival suitor, which he did at the Battle of Lugdunum, and that secured full control of the empire.

He inherited a partly troubled empire. The military campaign in Iraq had failed, borders were leaking badly and the economy was ailing. Gradually though, Severus began to unify an empire which had suffered badly during the turbulent period under Commodus.

He eliminated government corruption and nurtured the legal profession in an 18-year reign which ushered in the golden age of Roman jurisprudence.

“Severus realised if he was to succeed in the empire he needed the army on his side,” says head curator Andrew Morrison. “If you control the legions, you can easily usurp the throne. The soldiers really liked him and he improved their lot considerably.”

One way was by doubling their pay, but that along with Severus’s other policies began to place a severe burden on Roman citizens. The resulting high taxes would eventually play a significant part in the fall of the Roman Empire.

That and keeping huge armies in places like Britain.

“The Mediterranean was the financial heartland of the empire and getting rid of the furthest outposts would have made real economic sense. But like all emperors, Severus had an ego and wanted more to hand over than he inherited. “Heritage was everything to the Romans. Severus shared his emperorship with his sons, but in his later years realised they were not going to make good generals. So he brings them both to Britain, plus his wife and the entire imperial court, with the explicit idea of hardening them up in battle.

“And because the emperor was here, the Roman Empire was run from York for three years. So this triumphal procession arrives and the city became an exotic place, with new religions, new foods and new fashions.”

It was the beginning of a black and Asian presence in the north east of England. Something borne out by the limb proportions of skeletons unearthed in a Roman cemetery outside York, which revealed some of the men were black Africans.

It was again confirmed last year when the Ivory Bangle Lady was discovered, a high-status young black woman buried in York during the period Severus was in town. It was more evidence to contradict popular assumptions that African immigrants in Roman Britain were of low status, male and likely to have been slaves.

“We have Victorian school teachers to blame for the picture of how Romans treated their slaves. They were trying to justify what we were doing at the time.

“Anyway a Roman slave was simply somebody who was owned by someone else. Not all were treated badly and some were very wealthy. Indeed imperial slaves were advisors to the emperor.”

The third century was an enlightened age and in the empire, class held no barrier to high office – as Severus proved.

“During his time here, York would have been a very vibrant and cosmopolitan place. It has to be three of the most exciting years in the city’s history.”

• York’s African Emperor runs at the Yorkshire Museum throughout February and from Friday a bust of Septimius Severus, on loan from the British Museum, will form the centrepiece. For a full programme of events visit yorkshiremuseum.org.uk

• Precious Cargo is part of the National Stories of the World Project, which is part of the Cultural Olympiad; a series of events to showcase the UK’s arts and culture in the run-up to and during the 2012 Olympics.