Who is the Narrator?

I recognised the voice of the narrator of tonight's episode, the first in the series, so I was anxious to see the credits at the end to see who it was. But they ran them very quickly and in an odd order, so I didn't see it. So I first went to pbs.org, that didn't list any production info on the show, so then of course I went here to imdb, where I always go to look up stuff like this, because normally they have even the most obscure info on a show or movie. But instead of being listed right after the director, writer, and producer, where you'd think it would be, it was way down the list of extended cast and crew, and listed in the 'other' category.
It said Samuel West (unknown episodes). So does that mean he does infact narrate all the episodes or one and not the other, or two and not one? etc... Because I have to tell you he is not what I had in mind when I recognised the voice on the show. And I have never heard of this person. Imdb says he's British as well, and that was not a British accent narrating the programme. Unless he IS the narrator, but only of the British version, and there is a different American narrator, on that version? The only reason I say that is because at the end of the programme, where they tell you where you can buy the dvd, it gave the option of buying the British Version, so apparently there are two versions, and perhaps two different dvd formats I assume as well.
Anyway, maybe I was just imagining things, but I really thought I recognised the voice and thought I would know the person behind it once I looked it up, but that did not happen. So if anybody knows if this Samuel West is the actual narrator of either version of the show, of all the episodes, or if there is another person, please tell me who it is! Maybe it was just me, but it sounded like a male African American actor's voice. Sort of like Avery Brooks.

Thanks!