It is illegal to use your mobile phone while driving, but is it illegal to present a documentary about Ancient Rome while driving?

If not, it should be, because for some reason Mary Beard opened her new programme by explaining the intricate details of dynastic power in 41AD from behind the wheel of a fast-moving car and she didn't seem to be concentrating. "Caligula was born and grew up in Germany," she said. Really Mary? That's lovely. Now could you keep your eyes on the road please.

Then I worked out the reason for this lunacy. Documentary-makers are afraid of two things: silence and stillness. It means documentaries must be kept moving at all times because if someone stands still, producers think we might get bored. It's nonsense of course, but it's why the renowned classicist was forced to do the introduction to Caligula With Mary Beard (BBC Two, 9pm, Monday) from behind the wheel of her silver Astra.

Once she parked the car and got on with the show, it was excellent. No-one has taught Beard how you're supposed to look or sound on television, which means she is one of the best things on it. She also has a marvellous bloodlust for gory historical details and unveils them with a colloquial flourish.

Her thesis was that the Ancient Romans were just like us and she had some interesting facts to back it up:

1. The Romans had lots of public inquiries too. The one that Beard told us about was the investigation into the death of Caligula's father Germanicus and she showed us a copy of the report. No doubt Hugh Grant gave evidence to it.

2. Everyone needs a slagging off from time to time. Beard explained that the name Caligula was a nickname given to him when he was a boy, inspired by the fact he liked to dress up as a soldier, right down to army-issue footwear. The name means Bootikins and, when he grew up, he hated it because Emperor Bootikins doesn't quite have the gravitas needed for the role.

3. Leadership always leads to disappointment, or pain, or death. Beard told us how Caligula was killed when he was 28 when his bodyguard turned against him and there was some marvellously gory detail about the first blow of the sword which failed to kill him. Her point was that this is how leadership always ends, with your friends turning against you, and it is how it will always end.

4. If you want to get to the top, get a brand. Caligula knew it when he stamped his face on coins and had copies of his statue sent out across the Empire, and modern heads of state know it too. It's what the royal family is up to when they pose on the steps of hospitals with babies. It's the same thing. It all looks fairly modern, but it's not. Ancient Rome is still with us.