Without doubt this has been the most difficult book I have ever written.
My other books are on a variety of different subjects, ranging from a history of the labour movement in Northern Ireland to insurgency in South Yemen.
Although challenging to write in their own way, they did not pose the same unique problems as UVF: Behind the Mask.
Professional historians are used to scrutinising the past by way of documents and interviews with eyewitnesses.
They are supposed to triangulate these kinds of sources with what is already known about the past.
Sometimes this means challenging their own preconceptions and beliefs.
In the case of the UVF, this meant adjusting my own previous analysis on the group because some of the facts had changed as new evidence came to light.
Interestingly, as I neared the end of my project, these new facts augmented most of my previous analysis on the UVF, which was completed well over a decade ago.
More seriously, however, was the changing context within which I now had to conduct my research.
