Baron Edward Bulwer Lytton Lytton 
Rienzi, the Last of the Roman Tribunes [PDF ebook] 

A slightly convoluted romantic retelling of a most fascinating period in medieval Roman history. Just as interesting as a document of its own time as it is an interpretation of the history it represents. Bring it to life!
The story starts with two brothers getting into some brawl, the younger one gets killed by some members of the ruling families of Rome.
The other goes into politics and eventually becomes the last tribune. A man from the people. According to Lytton a true man and a political genius.
He fights against the families, gets rid of street robbery and other misery. People love him. People betray him. Great scenes, where Lytton describes how the mob changes mind.
He gets the beautiful lady. Sister is in love with one of family members. The good guy.
Rienzi is driven away from Rome ends up in prison in Avignon, returns because of a clever scheme by his wife who convinces the grey eminence that only Rienzi can get the Pope back to Rome.
In the end, Rienzi and the lovely lady get killed. Traitor is the young boy whom they had practically adopted but who turns up to be the son of Montreal.