"The Prince" is the important one, IIRC he wrote some plays and such too but Prince is where his name got associated with cutthroat politics. It's a pretty boring read but it's not difficult to understand, I read it when I was 14 and I didn't have any significant difficulties even though I lacked context in contemporary Italian politics. Even though I was bored out of my mind (i did not read this book by choice) its been a major influence on my life because it explains all the different ways your choices can have surprising results in the long run if they're planned well by you (or your adversary).

It's a book he wrote about how to maintain power in a feudal society, with references to many historical events to back up his arguments. Usually it comes down to being wary of accepting help from somebody else unless you understand their motivations, what they stand to gain, and what you stand to lose in the long run. It's sort of like "Art of War" in that it's written for a specific time and place but the principles behind it are so universal they can be applied to many different situations, even business management and interpersonal relationships.

So anyways, my point in the OP above was that this is the sort of situation that he wrote extensively about; obviously there weren't any computers or cloud storage in 15th-century Italy, but he definitely makes several points on the dangers of relying too heavily on third parties for resources, because it gives them leverage with which to manipulate them.