I don’t know how true it is, but supposedly the Romans really loved The Iliad and it formed a central, almost religious position in their culture as a backbone to the military tradition.
I was speaking from personal experience, Roots, 1984, etc. all had a profound effect on me. I never got into genealogy from Roots but it had a big impact on my 13-year old brain.
Les Miserables was supposedly extremely popular among the Confederate soldiers during the American Civil War (who read a censored serial version with Hugo’s abolitionist views removed) and Lee was said to give copies to his officers to carry with them.
My own copy has a forward talking about its influence in other revolts, revolutions and civil conflicts but the Civil War one is best remembered.