Anglo-Saxon England and Slavery

 Just finished Marc Morris book on Anglo-Saxon England, an interest partially spurred by the TV series "The Last Kingdom".  I liked it, given the scarcity of sources with which he was dealing.

One thing I learned--10 percent of English residents were slaves at the time of the Norman conquest.

I vaguely knew that the word "slaves" comes from "Slav"--from the internet:

What's the etymology of slave?

Etymology. From Middle English sclave, from Old French sclave, from Medieval Latin sclāvus (“slave”), from Late Latin Sclāvus (“Slav”), because Slavs were a common source of slaves, during the Middle Ages, for Europe, the Byzantine Empire, and Arabs.

And I know "slaves" are described in the Bible, etc., but the dominant image in my mind is the rise of African slavery in the mid 15th century, through to the mid 19th century. 

It's so easy to make the accessible information seem like the exclusive and essential information.