Roberts read thousands of Napoleon's own letters, and what comes out is not the cartoon general. It is a man running a country while on campaign, writing a legal code that most of Europe still uses, and answering questions about school budgets in the days between battles.
What stays with you is the pace. He worked while other people rested, dropped a loss the same day it happened, and started the next thing immediately. Eight hundred pages and it never drags. It is the clearest picture I have of how much one person can get done in twenty years.