One of Patrick Stewarts other famous roles was as Sejanus, a Roman tyrant who was quite arrogant and self-serving, in I, Claudius.
Stewart didn't disappoint in the role. Highly recommended mini-series and you'll see many other familiar faces.
Gold standard for Roman media. Shame Rome didn't get a longer run, it'd have had a chance of actually adding and maybe surpassing I, Claudius.
There was also a series called The Emperors that came out around the same time. You can find it on youtube. It's black and white and the audio has the occasional rough spots since the only surviving copy was in bad shape. It's a shorter series as well. The one thing it gets praise for is a better version of Tiberius. In I, Claudius Tiberius is a whiny guy being controlled by his mother. In The Emperors Tiberius is much more calculating and not bossed around by his mother as much. Both versions have something to offer but I do admit I like the Tiberius in The Emperors a but better.