On Foyle's War (2002): When the series first went out in the States, for example, at the front of each episode a rather eminent historian spent a couple of minutes on camera explaining how that episode related to the period of war it's set in, what actual incidents have inspired it along with various things to look out for during the course of the programme. I think it's a great shame something similar doesn't happen
when the series is screened in the UK. It undeniably adds another level
and depth to the programme, not to mention the success this sort of
prologue or introduction has had in the past - the Alfred Hitchcock series for example.