It's too easy and common to charge a dramatic event of reality with speculations and conjectures without end, looming over the real event like a mammoth over some butterflies, which was the true fate of this family tragedy, grossly embroidered by legend to irrecognizability. We shall never know the whole truth of what actully happened, but it is easy to look through and define all the artificial constructions.
The lover here is a castellan called Olimpio, who to my knowledge had no part in the tale. The real lover was a priest Orsino, who was in love with her before becoming a priest but who never could forget or suppress his love - later he had to submit to the pope for the sake of his position, like in so many cases, sacrificing and denying the truth for the sake of the career. The film is beautiful though and well made, nicely accompanied by dramatic music by Beethoven and Tchaikovsky (the 6th pathetic symphony used with great dramatic impact), among others. It's a sumptuos costume film, and there is even a delightful ballet scene and some other show scenes, although the general character is very formal and conventional, with wonderful genuine scenery and costumes of 1598. The film in its conventional outlook carefully hides and avoids any hint at what actually might have taken place, the unmistakable signs all pointing at a case of an incest intrigue and the fact that the entire family hated Francesco Cenci and had good reasons for it.
After the execution of Beatrice she inmmediately appeared as a martyr for a miscarriage of justice to hide the unpleasant facts of Count Cenci's dubious affairs with the pope. The entire mystery has never been solved, but Beatrice's martyrdom can never be taken away or obliterated from eternity and will always remain a subject of new speculations and conjectures.