The series was made in 1993 by Hartmut Kaminski who has long passed away now.
It provides a great amount of not-seen-before footage from soviet era, which makes the value itself for the series.
But the greatest thing is that the viewer enjoys the ultimate experience of the historical footage and is not disturbed by narrator trying to show his face to the camera, which is a disease of modern documentaries and they ruin them.
I watched the series to learn of Stalin rule as much possible, and I wasn't disappointed. Narrator's voice is pleasant and addition of historian Volkonogov brings an extra benefit.
There won't be any more such great documentaries ever done, even if new footage emerges from russian archives. Simply because times have changed, and modern directors lack skills and patience to understand how good documentary is made.
This series is superior to any sensationalist documentary made by BBC or any other past 2000.