Thank you for your considerate response, that is so sadly rare on the internet. I forgot about the fact I put both on their so I apologize for that my mistake. I do agree about the nobility being the hard part and as much as a part of me would enjoy killing them all it is probably counter productive. My initial thought is to confiscate their property and give it to our supporters or former slaves, the rich might hate it but they won't matter if they are no longer rich. Though that also runs into the problem of alienation them as much has killing them might when they still have social clout and connection to stir up trouble, no perfect solutions it is a matter of effort.
First of all, you're welcome. I always enjoy a good argument, no matter if it shares my position or not. Honestly a
good argument against what i say it's even better, as it possibly gives me something to learn, or a point of view i didn't consider. It's also more enjoyable. There is not much discussion to be had if everyone agrees from the start. And nothing kills a discussion like a "why? because i say so!"
Now, killing everyone is always tempting, but it risks gaining us sworn enemies. It's unlikely we'd get everyone, and in a setting with magic and world-ending villains we'd prefer avoiding those. Especially as those enemies would most likely be unicorns. We don't want another Sombra, or a Pony of Shadow, or a Nightmare, or whatever else Questor could come up with. We already have enough coming from canon without adding new ones.
confiscating their riches is a possible option, but we need to be carefull as well, at least in part for the reasons already written above.
Nobles are after all the more likely to possess dangerous magical knowledge in Maretonia. For all we know we might push them in a "deal with the devil" if we're not carefull. No more dangerous beast or person than a cornered one. Give them a way out and they might be willing to negotiate.
There is also the fact that, from a legal standpoint, slavers are not doing anything wrong. Immoral, certainly, but not illegal (according to their laws). And following laws is important if we want to mantain order and legitimacy.
I'm blabbering a bit, what i mean is basically:
1)Once/when we manage to get slavery abolished we should be relatively lenient with ex-slavers who are willing to be reasonable.
2)Once the laws we want are in place we should act (or push whatever Government there is at that point) to act decisively to enforce them. We don't want slavery to simply be pushed to the underground, we want it completely destroyed.
As much as I like arguments about history and would love to talk about the thirties year war (Have you read the 1632 series? it is great if a little bloated lately.), I am going to try to avoid that hear since it really isn't the time or place.
Overall, I am just going to say even though the direct definition and therefore timing of nationalism is debatable, I don't think it applies to Maretonia.
Even though we have some forms of more advanced technology then medieval or early modern tech as far as we have seen Maretonia is lacking in the presence of mass media that usually can be considered necessary for the kind of we have now even with magic. Maretonia and most nations right now are relatively young due to discord so likely hasn't really made a national identity like we have since their haven't even gotten control of their nobility yet. They don't have a unifying myth like we have made of the Emperor reuniting the broken kingdom and bravely fighting the dark wizard Sombra and all his horrors, we could possible give them that via invasion as a foreign invader but as you said a part of that is often that the conflict is long, protracted and brutal which we are trying to avoid. Based on what we see of Maretonia, where everything is run by a de-facto racial caste system with powerful nobles I don't think the free population get much benefit from it or see it as worth much as compared to the nobility who really benefit from it.
So yer while you are right about something close to nationalism being possible before the usual advent of it with the rise of mass media later on I don't think it will apply here unless things go very wrong with our approach.
about the unifying myth, they might have one that we don't know of. They might even have the same one as Equestria, The Fires of Friendships that brought an end to the conflict between the pony tribes (though if they do they're not really following the spirit of it, though they DO claim formal equality between their citizens and slavery IS applied to all three races (though to earth ponies much more than to the pegasi and unicorns))
They ARE (at least formally) beyond the time of conflict between the tribes (though i find likely (or at least possible) the existance of racial segregation laws similar to what the usa had in the past, along the lines of "
separate but equal". I'm definitely not an expert though, i don't really know that much about how it really was)
About the mass media...It's unlikely, but they COULD have at least newspapers. Have pegasi carry at least one copy of it to every town, then have local unicorns use some kind of duplicating/book copying spell, or some magical items with that kind of power.
Unlikely, but possible.
...on that note, do WE have printing tech?