Byzantines. Basically Game of Thrones on steroids plus constant migrations and far more sophisticated religion issues. Noses, eyes and "greyjoying" as a part of imperial policy. Also, Vikings, Vikings everywhere.
Russian Civil War - multinational, multicultural clusterfuck. Czechs controlling Transsyberian, western interventions, modern equipment being introduced - and single tank capturing a city, Far East being ruled by some psycho Ghengis-Khan impersonator, people from across all Europe - prisoners, deserters, adventurers, fanatics travelling thousands of miles trying to reach home, fight for a cause, get rich. Certain stories are actually less believable than average Hollywood blockbusters.
Spring of Nations - a revolt in multiple countries pulled off despite reactionary governments, closed borders and lack of lingua franca (in its modern sense) - and before Internet was even a thing. Young angry people, conspiracy, betrayal - and enough of social tension and individual drama for a metric ton of soap operas if House of Cards equivalent is not enough. Also, go away, Les Miserables, you are drunk and out of your league :/
Barbary Pirates. Because trolling Church of Identity Politics with Irish (and even Icelanders...) being captured as slaves by PoC raiders for a period longer than entire US history would never get old XD