Davis, Robert C. Christian Slaves, Muslim Masters: White Slavery in the Mediterranean, the Barbary Coast, and Italy, 1500-1800. Palgrave MacMillan, 2003 Amazon
What you might call “Mediterranean slavery”, of Christian Europeans captured through piracy or raids and enslaved in North Africa or the Near East, coexisted with Atlantic slavery, roughly paralleling the dates. While the numbers about Atlantic slavery are pretty solid, the numbers on Mediterranean slavery are far less so, and Davis is forced to piece together rough estimates from a variety of different sources.
Trying to pin down numbers of Barbary slavery is beyond the scope of this blog, and I don’t want to get into any kind of “oppression Olympics” about different slave economies. (Discussions of white slavery tend to bring out people with an axe to grind. One discussion of Barbary coast slavery on Fetlife included a post with a link to a white pride site. This included lengthy incoherent rants about the place of white people in history. One passage included an array of pictures of tribal people with facial tattoos or body modifications, followed by another array of white people with facial tattoos or piercings. The caption said that these white people took no pride in their heritage and were trying to imitate other races.)