I absolutely love these series. I watched a few episodes here in Norway on BBC knowledge, and immediately bought all the released series on DVD. I think this is one of the best and well-made TV-programmes I've ever seen. It's such an interesting concept and every episode is intriguing and exciting. I think for someone who likes history this is an absolute treasure. Every sequence is like a journey into a well-known person's family and then their family's history. And it is all done in a most fascinating way. For us, the viewers, and the celebrities/TV-personalities themselves, this is in fact also a very emotional and touching journey to attend.
In addition it is quite informative of bygone times and cites. The narrator often tells us a lot about the different places they visit; on how life and its conditions must have been there in these various eras of history, and for their ancestors. How did they live and work? You learn about how things were done in society; about dealings with criminals, WWI and WWII, you learn about conduct and family secrecy, the shame of an illegitimate child, and all such things. I highly recommend this.