Is it offically titled 'The Royal County of Berkshire'? Or is this just something they stick on the signs to jazz it up a bit? And whilst we're on subject, I recently discovered that ABingdon used to be the county town of Berkshire. So why was this and the surrounding area given to Oxfordshire in 1974?
Yes, Berkshire is a royal county - I think it was granted this title in Victorian times, because Windsor Castle, which is in Berks, was one of the queen's official residences.
I don't know when Abingdon was the county town - must be quite some time ago. There were many boundary changes in 1974 in the South East, so this must have been one of them.