Books small enough to take on one's travels was one motivation behind the invention of italic type. Using italic, a book could be printed to be 10 percent smaller than without.
I think one of the key ideas here is not just having a personal library – it's about doing focussed research to help conduct whatever military campaign you're going on, and having a librarian to help you do that.
So there, all of your assigned papers in college that had you do research were teaching you the whole time to build the French Empire!
"... Louis Sarkozy is a Franco-American writer. After having been raised in France, he moved to the United States and graduated from Valley Forge Military Academy and College... " [1]
and
"... He is currently applying to the United States Army's Officer Candidate School, where he hopes to start a career as an Army officer..." [2]
Makes it seem like he is preparing to be the next Lafayette in case China invades the USA.
