I'm probably going to be corrected by someone who knows better (Please! My notes from that trip have been lost so I'm not 100% sure) but I think this is an SE5A Fighter from WWI. I'm assuming it's a replica and it took part in a re-enactment flying display at Military Odyssey in 2007.
The SE5 performed better than its more famous rival the Sopwith Camel but engine problems meant it was always in short supply even up to 1918. Originally designed by the Royal Aircraft Factory in 1916 with the SE5A becoming available soon after. It was a very stable plane making it an excellent gun platform and easy to fly for novice pilots.
Its not often we get to see magnificent aircraft like these in our sky's and they are usually guaranteed to make you look up in awe when they do fly over.