I had always doubted that the word, slave, was the root of the ethnic origin, slavic. It seemed unlikely to me that even a conquered people would refer to their culture with the word.
Turns out I was looking at it backwards. The whites used the word slavic in reference to their slaves. Actually, the similarity in the 2 words just underscores the ancient practice of domination, explotation, and manipulation that the dominant use effectively against external groups, often based on ethnic designations.
late 13c., “person who is the property of another,” from Old French esclave (13c.), from Medieval Latin Sclavus “slave” (cf. Italian schiavo, French esclave, Spanish esclavo), originally “Slav” (see Slav), so called because of the many Slavs sold into slavery by conquering peoples. This sense development arose in the consequence of the wars waged by Otto the Great and his successors against the Slavs, a great number of whom they took captive and sold into slavery. [Klein] Old English Wealh “Briton” also began to be used in the sense of “serf, slave” c.850….