After Omega Glory, Patterns of Force and Piece of the Action, Gene Coon asks the Trek audience to buy yet another far-flung planet where the civilisation has evolved along exactly the same lines as Earth. It's a bit of a stretch and - by this point in the second season of what is otherwise the best sf show on tv at this time - it smacks of lazy writing.
At first, as the story unravelled, I thought I remembered that it was the rogue Captain that had introduced the idea of Roman imperialism to the planet. But no ... it turns out that the planet had invented Roman society all by itself.
All in all, this episode just kind of lies there feeling sorry for itself. The lacklustre script brings forth lacklustre performances from the cast. Only the banter between McCoy and Spock brings any semblance of life to the proceedings.
The true test of a decent Star Trek episode is, "Would I recommend this to someone who's never seen the show before?" In this case the answer is, sadly, no.