First of all tell me where the idea for Hello came about – where was your first Hello piece shown and what drove you on to do further Hello pieces, what excited you creatively about the piece?

Over a decade ago, I came across this postcard stand where there was a postcards of Princess Di who had just passed away. Then I there was another card of Mother Teresa who had died a week later. And in the middle, there was another postcard of the two of them meeting - something both obvious and improbable. Glamorous Diana had to bend over on her stiletto heels to shake hands with the hunched and tiny nun. They both were blue and white. This seemed very funny to me, and it started a long process of very intense exploration of human relationships and photography. Drawing on personal friends and family resources, as well as on public libraries and commercial image banks, I started building these very complex photo chains of encounters between people from all walks of life. The longest one became 333 images long and was displayed at the Curve Gallery at the Barbican in London in 2001, on an 80-meter long wall. In total, I have made seven versions in as many cities around the world - all locally grounded, but sprawling globally.

It's a six-degrees-of-separation style picture chain, and because it is mainly photo-based, it also becomes an investigation of the very nature of photography. I use found photography from every imaginable source: historical, recent, professional, amateur, political in intent or not. I work with a huge pool of information. The interesting part is to synthesize it into this one linear narrative.

I had heard you were not doing any more but were persuaded to do a specific one for Colchester, why was that?

Because it is both hugely labor intensive process, and also a winning formula I was not interested in simply repeating. For every picture you see on the wall, 10 others were considered, sourced, followed through on and rejected. This becomes hugely complicated when live people are involved, the ethics of asking people to share their private images are delicate and the arbitrary process on following connections that may or may not result in what you want can be very consuming. The mastery is really in what you don’t see, the editorial process. This also means I had to reject a lot of my material I had originally asked for, simply in order to follow through with the logic of the work.

When I originally worked on this project 10 years ago it was my sole project. I was able to travel on location and immerse myself in a community. Nowdays I am involved with at least 20 group exhibitions and several new commissions every year, so it would be impossible for me to take on this project by myself and stay with it throughout. I could only travel to Colchester once a week so would only be able to do it if I could have help and if that also pushed the work in a direction that I personally had not explored before

So on these conditions, and my request, the curator Michelle Cotton gave me an assistant, Asana Greenstreet at FirstSite who became my local anchor and followed up on many leads. We also hired a professional photo researcher to collaborate with us, Joanne King.

Joanne has worked with archival material for BBC televison documentaries for many years and was very familiar both with UK history (which as a foreigner is not my expertise at all). She also had access to the resources needed in order to dig up all the fantastic images involved. While Asana and I went door to door in Colchester, focusing on the local contemporary part, Joanne mined the art libraries and archives for historical material. I would overview the whole process and we met in the middle.

The history of photography starts (or ends) in my piece with a Victoria photograph, thereafter we had to rely on prints and paintings which Joanne brought 4 centuries back in time to the meeting between Queen Elizabeth I and William Gilberd. This has been a completely new method for me in and has definitely pushed this version of the work much much farther than before.

Did you discover any common traits from the Colcestrians you met? Were there any particularly inspiring people?

Everyone who contributed to the piece and whom I had the privilege to meet were inspiring. There is one theme that runs through this version of the work, that of History, both factual History and reenacted history. In several cases people appear in period costume. I would hate to generalize a whole town population but this might be a particular Colchester trait.

I believe the picture that started the whole process was one you found in our newspaper – is that right? Why did you choose that one?

I saw the photo of Ashley James Hall and Queen Elizabeth II in the Colchester Gazette on my first visit to Colchester. It had everything I was looking for, a local person with a celebrity. We tracked down and contacted the family who were happy to be involved and contributed the next image. In the final presentation is appears as the central image from which the piece expands in two directions, one present day of regular folks and the which stretches back in time through past royalty and their entourage.

What do you think of our swanky new gallery and how pleased are you to be involved in the opening show?

I had great fun in choosing a wall for my piece. I needed one long uninterrupted wall and what was available is simply the curve which also leans in a 45 degree backwards angle. I could not have dreamt of a better space so am very happy!