Genghis: Birth of an Empire

I'm a few years removed from reading both history and historical fiction on Genghis, so his story is very much muddled in my brain. The story progresses pretty well and the characters and their lives come to life. A couple things I was iffy about he actually mentions changing in his postscript... although I'm still not sure I get "why" he made the changes in some cases. Good enough I'll probably read the rest of the series, but not so good that I'm in a rush to do so.