I had supposed that the construction ‘the reason is because . . . ‘ (rather than ‘the reason is that . . .’) was of recent origin. In ‘The Penguin Guide to Plain English’, Harry Blamires will have none of it, calling it ‘causational overkill’. I hear it increasingly to the extent that the ‘because’ form now seems more frequent than the ‘that’ one. Ah well, I thought, I can see Blamires’s point, but usage rules and we must accept this new construction.
Until, that is, I happened to be reading an extract from the Putney debates of 1647, when Cromwell’s New Model Army met to decide what to do with its victory in the Civil War. And what do find? We find one John Wildman saying this:
Our very laws were made by our conquerors; and whereas it’s spoken much of chronicles, I conceive there is no credit to be given to any of them; and the reason is because those that were our lords, and made us their vassals, would suffer nothing else to be chronicled (my emphasis).