After a bit of research it turns out this is a Moon Ring (or Winter Halo). A phenomenon caused by the refraction of light in tiny ice particles in the upper atmosphere, and only appears on a cold winters night around the time that the moon is in it's full phase. What makes this sight even rarer is the fact that it can only be effectively observed at a certain angle, and only lasted for around 2 hours from midnight onwards.
It made for a fascinating sight, and just to give you an idea of the size of the ring, the first image was taken with my wide angle at just 15mm.
Moon Ring by Samuel Pilcher, on Flickr
Moon Ring by Samuel Pilcher, on Flickr
Sam
