It all began with Prince William’s knee. Not, of course, the phone hacking and bribery and corruption which, as we all now know, was commonplace behaviour in the British tabloid newspapers at the heart of Rupert Murdoch’s media empire – that had been going on for far longer. But when, in November 2005, the News of the World carried a trivial story about the prince – ‘Royal Action Man’ – receiving treatment for a strained tendon, he and Prince Charles’s staff realised that this and other leaks could only have come from someone accessing his voicemail. St James’s Palace, fearing a security threat to a future king, called in the Metropolitan Police.