It's not something that can be quickly learned over the internet. It takes dedication and hard work. Plus, being born into the "right" family helps quite a bit.
There's no better way to learn than by watching your father crush his enemies, see them driven before him, and to hear the lamentations of their women...at his feet. In time, IF you learn well, he'll give you the opportunity to try it yourself...probably with a small village at first, then, as your skill improves, he'll let you move on to bigger enemies...and eventually, on to entire civilizations.
Everyone knows this.