It's well known that the Roman Empire made use of slavery, but how widespread was the use of such an institution after Roma's collapse? I assume the economic shift must have been large while varied, and the trade spurred by events such as the wars, but it's difficult to think the practice didn't evolve throughout or after the dark ages. Moreover, was it ever racial, and how long did the practice take to wane in popularity?
TLDR: Southern European slavery in Medieval times, what was it like?
(Sorry for the loaded question. Comments are much appreciated!)
Slavery existed in western Europe through 11th century, there was nothing racial about it.
Frankish and Carolingian society was built on tremendous slavery
vikings took Anglo-Saxons into slavery
vikings took Slavs into slavery
Moslem raiders took slaves from raids on southern France (Provence and the Rhone)
And slaves were not just 'taken' but also sold, all of the above crossed into sales of the slaves into the other territories. There are numerous references to Frank merchants shifting slaves into Moslem Spain, particularly in the 10th and 11th century when we begin to see the post Carolingian pressures on domestic economy transform the nature of the Frank manse. Slaves were a commodity that could be converted to capital.
Once the slave was no longer a viable economic model (ie fixed expense to the estate), we see the conversion of the slave into various forms of serfdom and peasantry which were more flexible cost types (ie variable expense). This didn't all happen at once, and it didn't all happen the same way across western Europe.