I read an interesting blog post by Leigh-Ann Anderson called Choosing a Magickal Name. It give some interesting ideas on how to choose a magickal name, but it doesn't approach the topic historically.
Magickal Names in the Past
Anciently, there's no evidence that people used magickal names. While this may be because magickal and mundane lives were one and the same, I'm more inclined to believe that they simply weren't needed. The need for a magickal name developed as the military might of the Christian Church expanded. If you were caught doing magick, you could be imprisoned, tortured, or killed…but not before you revealed the names of your "co-conspirators." So people would take on