There are annoying bits, of course. I could do without Cleopatra's bikini bottoms, which make her look just a bit too much like a porn star. Augustus' narration of his past by slipping into lengthy anecdotes at the end of arguments is clumsy, and makes you think everyone around him must have thought he was really, really boring. And my jaw bounced off the floor when I realized that the incredibly camp individual introduced midway through the first episode is meant to be Augustus' literary-minded friend Maecenas.
There's some whiting of people out of existence. Maecenas disappears after the conquest of Egypt, with no hint that he continued as Augustus' helper for a number of years yet. Gone are Cleopatra's son by Caesar, Octavia's children, Livia's second son Drusus and his sons Germanicus and Claudius, and Julia's daughter Agrippina, and the son with whom she was pregnant when she learnt that her husband Agrippa was dead. Agrippina's absence is particularly curious, as the series ends with Livia ensuring that Tiberius will reign after Augustus, and Augustus saying that 'Your son's blood will run in future emperors, not mine'. Yet by making Tiberius adopt his nephew Germanicus, who was Agrippina's husband, he actually set it up so that his blood would run in future emperors, after a couple of generations (as indeed happened).
But there are so many good bit. Nice little architectural touches, like the ships prows on the rostra, or being able to work out from the shape of the altar that a building is the temple of the Divine Julius before the dialogue tells you. The series remembers that Octavius insisted on being called 'Caesar' after his adoption. It finds space for calling the Senate 'conscript fathers', the reading of Antony's will, declaring war on Cleopatra rather than Antony.
Augustus' life is not easy to dramatize. Much of it is a tale of political reform. Most treatments of him either end with Cleopatra's death (Cleopatra, Rome), or pick up with the dynastic scandals of his later life (I Claudius). Imperium puts both together, running the story of Octavius' rise to power in parallel with the events leading to the Julia scandal. They do succeed in creating a coherent narrative.
Of course, the shadow of I Claudius hangs over this series, but it makes that work for it. Charlotte Rampling's Livia is presented in such a way as to play with perceptions raised by Sian Philips' Livia. The audience expects her to murder everyone between Tiberius and the throne, and the first episode ends with her apparently poisoning Julia's children - but she actually doesn't do it. Though she considers leaving Augustus to be assassinated, in the end she can't do it.
And then there's Peter O'Toole's Augustus. He doesn't get something as meaty as 'Is there anyone in Rome who has not slept with my daughter!', but where Brian Blessed's Augustus was losing his touch, and manipulated by his wife. O'Toole's is a relatively kindly man, but nevertheless, still in control, and aware that sometimes he has to do unpleasant things. I suspect the real Augustus had a touch more of the ruthlessness of Roddy McDowell's Octavian in Cleopatra, but this is one of the most complex portrayals of Augustus that I've seen. It helps that this is a European production, and so, unlike many American films and shows, is able to view the Roman empire as something positive that deserves saving, rather than an inherently corrupt oppressor.
So it's a surprise when the very last line of the film is 'In the twenty-third year of my reign, in the province of Judaea, Jesus of Nazareth was born'. This is exactly the sort of reference to the coming of Christianity that Quo Vadis and Spartacus have. There, it's meant to show that Christianity will sweep aside the corruption of the Roman empire, and make the world good again. What it's doing here I'm really not sure.