Well I have not the faintest idea how accurate this mini-series is historically but it's not as bad as previous IMDb reviewers have suggested.
It is a talk-athon and some of the dubbed actors are really out of their depth. The young Augustus is played well, multi-layered and rather complex and unpredictable. Mark Anthony and Cleopatra are an aside, and performed in a bland obvious manner. Charlotte Rampling is frighteningly real.
But it is O'Toole's show all the way as the older Augustus.
After 30 years of "wafer thin ham" acting this and his performance in "Troy" show what an experienced actor can do with a good part. It is a grand part for an actor and makes the 3 hour journey quite moving at times. So the grand total as an entertainment experience is....6/10