A book which goes into this in detail is:<p><a href="https://www.goodreads.com/book/show/40718726-genghis-khan-and-the-making-of-the-modern-world" rel="nofollow">https://www.goodreads.com/book/show/40718726-genghis-khan-an...</a>
If you enjoy a bit of historical fiction then I can recommend Conn Iggulden’s Khan series - <a href="https://www.goodreads.com/book/show/13573316" rel="nofollow">https://www.goodreads.com/book/show/13573316</a><p>I read them a couple of years back and thoroughly enjoyed them.