[quote=Danko]
While I thank you for your input please keep in mind this is a fictional version of our world. In this world slavery in Europe was never abolished, the relevant policies by the different countries you have mentioned never came into being. The institution of slavery in this world isn't out of the blue, it's been there for a long time and was never dead. The main changes in slavery throughout history in this world are the peoples who are being enslaved.Plus this is a setting for an adventure story, I'm not a historian, nor am I a sociologist or expert on slavery. Just a history enthusiast who wants to create an adventure story that I can enjoy with some like minded people.
[/quote]

I still creates plot-holes big enough to sail the British Navy through. And the existence of the British Empire as it exists and Austria-Hungary to be around would suggest that in some way the European Enlightenment came to being, and with it the crash-course for abolitionism in Europe.

You simply can not keep a system like slavery running in a world of growing national and social consciousness. When Empires span across half the world and have in their borders so many different cultural ideologies it'll inevitably introduce ideas of pluralism in society and religion. If the system didn't break when it did on the real time-line, it would have sooner or later. The French Revolution would have seen to that and the Age of Liberalism.

I frankly can not find a lamp-shade big enough to hide the fact.

And slavery only really benefits a certain type of economy, namely the agricultural estate-holding economy. In societies who have industrialized - as would have happened in much of Europe by this point - the work of machines and industrial organization would have lessened the cost of labor enough making slavery a moot point. And no pay for work more dangerous than swinging a sickle in a field of wheat tends to make people angrier. Just ask czarist Russia.