Of all the 'Carry On' films, I would have to chose 'Carry on Cleo' as my favourite. The main reason for this is the sheer genius of casting Kenneth Williams as Julius Caesar. His line - "Infamy, infamy, they've all got it infamy!" never fails to induce side ache. Of course, the film takes outrageous liberties with historical accuracy (we would be disappointed if it didn't). I never thought I would find anything of historic value to write about here. But, I was wrong. If you look carefully enough, any film can tell you something about the time in which it was produced.
There is a scene where Caesar/Williams is delivering a speech. He announces "Nihil expectorum omnibus" and translates this to mean "No spitting on public transport". Having a GCSE in Latin (I was one of the lucky generation that received a classical education in a city comprehensive) I could roughly translate the real meaning and laugh at the amusing Carry On aside. But I never fully understood why that line could amuse - I thought it a little eccentric for a film genre known for a more direct form of humour. It seemed a bit Monty Python. But then a read a newspaper report a couple of weeks ago. This discussed one London Borough's possible return to a spitting ban. Apparently, spitting was a criminal offence until quite late on in the 20th century. Of course, this was a relic of the TB age, when spitting was widely feared as a means of spreading the disease. The report went on to say that "Spitting Prohibited" signs were often seen on public transport.
This was all a total revelation to me. Now I see that Williams' line was based on something that to many viewers would have been part of the furniture of their lives. The moral of this is, if you find something that you don't quite 'get' in a film, it's worth having a little dig around in the history of the times - you might just dig up a whole new seam of knowledge.