Notably, all the "Early" slavery accounts are of either non-Christians, or Christians setting slaves free: enslavement of Christians I am pretty sure was prohibited by the high middle ages, and most serfs were Christians, and foreigners were not extremely common in the medieval period (highly localized society).
Later accounts, after 1400 or so, don't really apply to BM, IMHO.
Only these two seem really significant:
A transaction between Ermedruda of Milan and a gentleman by the name of Totone recorded in 725 the price of 12 new gold solidi for a slave boy (referred to as "it" in the record). 12 solidi was much less than the cost of a horse.
In the early ninth century, the Abbey of St. Germain des Prés listed 25 of their 278 householders as slaves.
Probably, I will get around to research on this in.... a week. Maybe two.
