How to make the neighboring dynasty was stronger ? (The Guild 2)

Hi all, I've been playing Guild. A great experience, so start to lose interest. No matter what difficulty I start, but the next dynasty very quickly zaginayus. I would like to find out how you can make them long lived, is constantly evolving ( in terms of industry and Finance ) and it was not easy to get rid of ( to kill every last one of them to take the whole business with the house, etc.).