Not just the documentary ... but really do encourage anyone that's really interested to listen to the podcast which goes into much more detail than the documentary.
https://www.bbc.co.uk/programmes/p08yblkf/episodes/player
I've been listening to this weekly podcast (from the same chap that did the BBC TV documentary mentioned by @Easy 10 ) ... really well put together and makes for interesting listening.
https://www.bbc.co.uk/sounds/series/p0cxg1j8