I was flicking through an old copy of The Spectator the other day, one of the issues containing contributors’ ‘Christmas Books’, and there was a comment of Jonathan Sumption’s that ‘as a general rule, biography is a poor way to learn history’. It is primarily a matter of approach rather than simply subject of course, but if one was drawing up a shortlist of men who might qualify as exceptions to the rule, then Philip Mansel’s ‘King of the World’, Louis XIV, would surely be very near the top.