My friend, colleague and former doctoral student Professor David Britain once told me that, of the papers I had written, the ones he enjoyed reading most were those where it seemed as if I was telling a story – particularly, he said, where they were detective stories. I had never thought of myself as writing detective stories before, but I did come to realise that David had offered an insight about my work that I had never been clever enough to arrive at myself. Some of my writing has indeed consisted of articles which begin with a historical-sociolinguistic puzzle, and then attempt to come up with a solution on the basis of the available evidence. And they are, I now see, written in such a way that the reader is left waiting to find out what the solution to the mystery is until the very end of the story. Even if there is no punchline as such, there may well be a final punch- paragraph.

This book, then, is made up of a number of such historicalsociolinguistic tales of detection which I hope, individually, will tell a coherent story; and which will also, I hope, combine to produce an overall, more general story which is also coherent.