"Quo Vadis" (Memoria of the First Holy Martyrs of Rome)
Here is Peter Unstinov as the Emperor Nero in the 1950's film of "Quo Vadis". I understand that the book on which it was based was well researched by the author, Henryk Sienkiewicz. Here is a piece on it from the blog Tea at Trianon. I understand there is a modern version of the film. Though the novel received accolades, the 1950's film now looks quite dated. For my money the best Roman epic film of all time is "Gladiator"