Why was Napoleon interested in expansion?

Okay, I have done a lot of research but I want to be sure I am going in the right direction. People argue that his ego and personality backed by the French Revolution and Enlightenment were a large influence on his expansion. Also, he idolized Julius Caesar and the Holy Roman Empire, and he wanted to expand for the betterment of the French Empire (money involved in ruling different states) and take over Britain by conquering all of their allies and trade partners. Are there any more MAJOR reasons than these?