Some of the TV programmes he brought into being are very significant for a UK audience of a certain age (Arena for me). If the ones mentioned in the Wikipedia article don't resonate, there isn't much that will be significant for you.

I remember him as a high level BBC executive in charge of programming, but I believe he was a presenter for a long time before that, concentrating on documentaries and journalistic pieces, particularly on the arts. He had a reputation of being very good at what he did, and I believe the period he was in charge is seen as a bit of a golden era for the BBC, especially for those not from the classical Oxbridge background.