the decline of human slavery in the Feudal Era

by Eron12 with Hero Forge

-Akeem, Professor Emeritus of Magicland

"Most Scarterrans with a cursory understanding of history have heard that in the ancient past, large numbers of Scarterran humans (and gnomes) lived and died as slaves.
Nowadays, slavery of humans is rare and slavery of gnomes is all but unheard of, Basically slavery of any non-goblin is pretty rare. I'm not going to going to talk about about the few hold-outs that still enslave humans or the practice of goblin slavery today, but that does warrant discussion in the future.
Most Scarterrans, especially those who aren't especially well read (and even some who are), well say that slavery of humans is mostly gone because of one compelling reason and all other supposed explanations are wrong.
I believe that many factors led to the decline of slavery, so for completeness I am covering of a summary of all the major theories plus a rebuttal for each of the major theories."

Vladimir the Conqueror ended slavery

Vladimir the Conqueror is the most feared and hated vampire in all of Scarterra's history. Vladimir liked being feared but he didn't want to be hated. He wanted the win the hearts and minds of the people he ruled, a tall order to be sure for a blood sucking undead tyrant, but he tried.
One of the things Vladimir did to show his supposed benevolence was to immediately outlaw slavery in any territory that he conquered. He frequently made brutal and bloody examples of slave traders and slave owners unless they freed their slaves and simultaneously bent the knee to Vladimir in a loud public ceremony.
Vladimir had hundreds if not thousands of vampires serving under his banner but he had hundreds of thousands of ordinary living humans serving under his banner. A lot of these humans were acting out of fear (like many who serve living feudal lords today), but some had true loyalty. A lot of Vladimir's most loyal human retainers were freed slaves.
If an area he conquered had an anti-slavery underground resistance, he would try to co-opt them into his spy network. While very Nonagon members joined Vladimir outright, a lot of the Nonagon members were opposed to slavery and were opposed to undead, so putting their anti-slavery and anti-undead ideals at odds was a good way to divide and confuse his opposition.
After Vladimir the Conqueror was slain and his short-lived empire was dismantled, a lot of the newly emerging (or re-emerging) kings and warlords wanted to reinstate the practice of keeping human slaves, but they opened themselves up to a lot of harsh criticism.
Lots of jesters and bards echoed some form of the phrase 'You don't want to be worse than a vampire, right?' This made it untenable for most lords and ladies to keep human slaves.

Free workers are more productive than slaves

by Eron12 with Hero Forge

-Danuta, matriarch of the Fumayan Masks

"Slavery is morally repugnant but that is not why slavery was abolished in most civilized lands. The fact that a lack of slavery is ethically preferable is merely a side benefit.
Even though they are not paid actual wages, slaves still need to be fed, clothed, and sheltered. Free workers only need a little bit more pay than the bare minimum needed to feed, cloth and shelter them.
A slave will only toil just hard enough to avoid the lash. A free worker who is supporting his family is going to work as hard as he can as long as he believes that his lord is treating him equiably.

A slave owner must hire overseers and guards. Overseers and guards must be paid, and they need to be equipped with armor and weapons. Free peasants still need to be watched to make sure they aren't slacking off, but they don't require near as many overseers and their overseers needn't bear arms and whips. This saves a lot of money and lets a lord or lady use the savings to hire additional workers.
At some point, an owner of slaves is going to have to deal with their slaves trying to escape or they are going to have deal with their slaves seeking revenge. Some groups, like such as the Lanterns, will attempt to aid slaves in seeking their freedom and to brutally punish those who trade in slaves or to punish those merely own them.
Rich people always have enemies driven by envy. If you are rich and have slaves, your enemies have ready-made in allies via your slaves. Since slaves are socially invisible, slaves are very good at overhearing things they shouldn't know. Slaves will not hesitate to share their masters' secrets with their masters' enemies.
This means slave owners need even more guards and overseers, not just to whip their slaves to make them work harder, but also to keep them in line and to keep enemies away. If an overseer of free peasants slacks off on the job, the lord has a end of the year harvest that is slightly smaller than he wanted. If an overseer of slaves slacks off on the job, the lord gets his throat slit in his bed while his wife and daughters are ravished."

Changes in warfare led to a decline in slavery

"I don't want to get into a philosophical debate on whether enslavement or death is preferable for the victims, but at at this point, few human conquerors have much incentive to take slaves during war.
In the immediate aftermath of the Second Unmaking, most humans (and elves) lived in relatively small tribal groups.
Initially when rival tribes went to war, the winning side would slaughter all the men of the losing side and absorb the women and children into their tribe and eventually make their 'war brides' and 'adopted children' full tribe members.
As tribal chiefs gradually became warlords and warlords became petty kings, the number of intertribal wars decreased but the size and scale of these conflicts increased. With the new scale of warfare came a new scale of oppression with victors of wars would instead enslave the populations of those they conquered. As petty kings became emperors, empires concocted very large military campaigns and would often enslave entire large populations in a single campaign enslaving tens of thousands of people in a single campaign. This was often how soldiers and their commanders received a large portion of their pay. If common soldiers did not want or need slaves, they would still get a monetary bounty for each slave delivered.
Ultimately, the various human 'empires' all collapsed for various while the Elven Empire endures. The Elven Empire never practiced slavery of humans or gnomes and this may have been one of the many factors giving our great empire stability. But that is neither here nor there. Instead of human emperors maintaining control with a flimsy bureaucracy backed by crude force, now we have human kings maintaining control with a system of feudalism loosely inspired by the Elven Empire's system of governors.
This new feudalism is a lot more stable than the empires of yesteryear. Also, their structure makes slavery impractical. Feudal human lords still go to war with their neighbors but gone are the large scale conquests of antiquity where thousands of people find themselves living under a new banner during a single day are long gone. Feudal kingdoms have a lot of bloody skirmishes where relatively little land changes hands, so enslaving entire populations isn't very effective.
Often, feudal era wars involve a lot of small scale raids to steal silver, reagents, and livestock. Sometimes civilians are killed or raped in these small scale raids but they are rarely kidnapped and enslaved.
Even if land does change hands, this doesn't change the social status of the most of the conquered people. Slaves belong to their masters. Serfs belong to their lands. Even if they don't technically belong to the land, most free peasants effectively are tied to their local farms by circumstance if not by law.
In most cases, a serf living on conquered land finds his day-to-day life is unchanged, he just pays his taxes to a different lord. Same thing for most free peasants. It is usually not in the conquerors' best interest to treat their new 'free citizens' substantially different than their old lord did. They want to get the farms up and running again and this is easier to do with the carrot rather than the stick to use a human metaphor.
Many of the darkest and bloodiest human wars of conquest are motivated by overpopulation. The aggressor side wants more land, so they want to displace another land's farmers with their own. This is terrible, because the losers are often killed or sent into the wilds to starve, but at the very least, a realm with overpopulation is not going to seek out slaves (because slaves represent new mouths to feed).
-Tarsynora Craroris, grey elf historian

Gnomes led the abolishment of human slavery

-Beslyfle, matriarch of the Fumayan Tenders

"Whether due to Maylar's influence or Turoch's influence or something else, it is the base nature of Scarterrans to seek to dominate those weaker than them.
For all our hidden strengths, gnomes are physically weaker than humans. For much the Red Era, a large portion of gnomekind lived in bondage.
The Order of Delas did and does a great many good deeds, large and small. The Order of Delas often fights with quills and coins, but we...errr... they... are not averse to using cloaks and daggers when the situation calls for it.

A lot of prominent owners of gnome slaves met mysterious accidents. A lot of high status human lords that were publicly against the practice of slavery found gnome merchants and money lenders giving them better deals.
The Order of Delas prioritized the welfare of gnomes but most were also against human slavery. But the abolition of gnome slavery usually led to the abolition of human slavery. The major exception to the rule are the Dark Elves of Kahdisteria where they outlawed gnome slavery over a century ago but have over a million humans and half-elves still in chains.
Sometimes gnome slavery was ended before human slavery but not always. In each land where slavery was outlawed, slavery was rarely abolished overnight. Usually slavery declined in popularity for decades or even centuries before it is officially outlawed. Often, gnome slavery diminishes to practically nothing, then human slavery diminishes to practically nothing, then a king or queen creates a new law officially outlawing slavery of humans and gnomes in the same document once nine tenths of the slaves are already freed. Whether the king is genuinely against slavery or is merely bowing to societal pressure is irrelevant, the end result is the same.

The Nonagon ended human slavery

by Eron12 with Heroforge

-Zajac of the Fumayan Lanterns

"We Lanterns don't agree on much, but we are pretty much in lockstep agreement in our opposition to slavery now. This wasn't always the case.
Going back many centuries, everyone agreed that they didn't want to be a slave, but few agreed that slavery itself was a bad practice. In ancient times, people outspoken against slavery were rare but a lot of them were Lanterns, or rather 'Seekers', the nickname Zarthus worshipers had before 'Lanterns'.
Not every Seeker was against slavery, some were sort of against slavery but made exceptions for enslaving 'amoral people'. But eventually the Seekers either ostracized or converted the hold-outs and once the Seekers were universally against human slavery, we were able to get the Tenders and Rovers. The Tenders opposed slavery because it broke families, fostered cruelty, and perverted the idea of communities. Rovers opposed slavery because it was an anti-thesis to the divine right of Free Will.

With the Rovers and Tenders on board, they were able to convince the majority of Stewards of the Dominion to join them. The official doctrine taught by most Dominion Stewards is that slavery is a perversion of the natural order. Then they converted the Stewards of the Gift and the Steward of the Gift were able to put a lot of leverage on secular lords.
Between the pressure of secular lords and the Tenders, the Guardians adopted an anti-slavery stance, already leaning in that direction because they prefer honest willingly given work. Together the Guardians and Stewards eventually got most Keepers to oppose slavery, or at least human slavery.
With weight of numbers against them, the Masks took up an anti-slavery position and pretended it was their position all along. A few Children even espoused anti-slavery beliefs but they phrased it as 'you kill your enemies, you don't enslave them".
Of course, the Testers say the strong should dominate the weak. Even they have some anti-slavery members, but most state there is no moral reason not to keep slaves, only practical reasons not to keep slaves.
In any event, once the near entirety of the Nonagon was against slavery, the kings and queens throughout Scarterra had to follow suit or find things become very difficult for them as they faced economic, social, and political pressure while also dealing with slave uprisings backed by powerful theurgists.

The elves led to the end of humans enslaving humans...by accident

by me with Hero Forge

-Gaatha of Musseland, local Lantern of Zarthus

"It is well-known that the dark elves of Kahdisteria collectively own more slaves than the rest of Scarterra combined and about half of these slaves are humans.
After the Great East Colassian war, the dark elves have (mostly) stopped raiding human neighbors to capture slaves but they have kept their slave population up with forced breeding.
As recently as four hundred years ago, some of the nations that are now part of the Colassian Confederacy had human slaves. Back in the Red Era, almost all of the East Colassian human tribes kept human slaves.
The Great Colassian War lasted about a century, but the millennium prior saw a gradual escalation of brushfire wars. These brushfire conflicts between East Colassian humans and dark elves gradually applied pressure on East Colassian leaders to 'not be like dark elves' led to the manumissions of all the human slaves still serving human masters in East Colassia.

I understand that Scarterra is bigger than just East Colassia, but in ancient times, the dark elves often raided the shores of Umera, West Colassia, and especially Penarchia for new captives. In modern times, sailors and traders spread tales of the dark elves far and wide. The poor reputation of dark elves proceeds them and people around Scarterra want to 'not be like dark elves.'
The wood elves and grey elves claim their ancestors never had slaves, even goblin slaves. This claim that they never had slaves is laughable, but it is clear they haven't had slaves in a very long time. In order to not be tarred with the same brush as dark elves, wood elves and grey elves tend to be staunchly anti-slavery, at least in word if not deed.
Wood elves are influential to humans in West Colassia and grey elves are influential to humans in Khemarok and Umera. This helped push anti-slavery sentiments in their spheres of influence.