Steve St Clair was born in western Virginia and runs an IT consultancy business in New York far from the picturesque remains of Castle Acre Priory.

But after becoming obsessed with tracing his biological roots the American made the 3,484 mile journey from his home in Berkeley Heights, New Jersey, to a quaint village at the heart of Norfolk.

It was at Castle Acre that Mr St Clair believes a distant ancestor witnessed a charter to give the priory churches and lands.

Ricardo de Sancto Claroo witnessed the 1085 charter of William de Warenne and Mr St Clair has found other connections to de Warenne and other powerful Norman nobles.

He said: 'It looks like my ancestors must have been very bad boys during the conquest. They seem to have been very worried about their souls.

'They have poured money in to building churches.'

Using a DNA database Mr St Clair has been able to connect other families to his own and has seen that there are many more links around Norfolk and in Hertfordshire than he first thought.

He said: 'For me getting myself on the ground is wonderful. I am able to see things I would not otherwise.

'For instance there is a village a stone's throw from Castle Acre called Newton and that is a name that I have had a match with.'

Mr St Clair's genealogical journey began as his reaction to the September 11 attacks in New York, which left him with a desire to know more about his ancestry.

He said: 'I started doing genealogy in 2001 right after the 9/11 attacks. I guess everyone reacted to that in different ways and this was just mine.

'It became a sort of compulsive obsession.

'After a good start I quickly became stuck in the 1800s.'

It was this roadblock that led Mr St Clair down the DNA route.

After finding a friend who had traced his roots back to a Scottish emigrant to Virginia in 1698 called Alexander Sinkler they decided to take a DNA test to find out if they were connected.

With the result a hit they decided to step up their efforts and launched the St Clair Research project.

Since then they have carried out more than 270 DNA tests on St Clairs, Sinclairs and Sinklers along with other connected surnames.

Mr St Clair said: 'Surnames were fluid back then there are examples where you see a guy who is the son of someone but he takes a completely different name.

'I use books to find these connections and then the DNA helps us to be as definite as we can about it.'

To find out more about the St Clair Research Project visit http://www.stclairresearch.com/.

Do you have interesting ancestors? Write to doug.faulkner@archant.co.uk