I’ve read two books by Machiavelli: The Prince, which is his best known work, and Discourses on Livy, which isn’t.
The two books have some likenesses but are fundamentally different. The Prince was one of two books which got me started on classical history, it is far briefer than the Discourses and contains a rather different message. I’ve also re-read bits of The Prince many times (and even have an audio book read by the sadly departed Ian Richardson), whereas I’ve only revisited the Discourses once or twice.
The Prince is a strange book, perhaps explained by the specific circumstances that led to its creation. It was begun after the Discourses, when Machiavelli was languishing on the scrapheap of public life. He had been part of the government of the short-lived Florentine republic, the city having previously been and subsequently become the property of the de' Medici family. Machiavelli wrote the book for the de' Medici, beseeching them to help Machiavelli return to public prominence and prosperity.
Because the book was written quickly it is both quite thin and lacks any distracting fripperies and digressions. However, it still manages to contain a wealth of brilliant insights by Machiavelli, concise lessons in classical history, 15th century examples of successful power politics and insights into human psychology. It is not a book with happy theories where people are always good and lawful but takes account of both human frailties and potential, albeit with the assumption that conflict is inevitable.
The book’s primary message is of how a man ought to attain power (and become The Prince), and was written for a powerful man during an era when Italy was split and rudderless as a nation. This was in stark contrast to more powerful and unified nations such as Spain and France, and Machiavelli wanted to rectify this situation.
Machiavellian has become a term used to describe people of an intelligent, devious and amoral nature, but I think that a little unfair.
If The Prince is a manual on acquiring power, the Discourses is an explanation of Machiavelli’s preferred system of government. In it, he (perhaps surprisingly) backs an approximately Roman idea of a republic, with strong democratic elements.
Anybody familiar with Polybius’ descriptions of the Spartan or Roman regimes will recognise many of Machiavelli’s comments in the Discourses. Given the choice, I’d always buy or read The Prince, though it is worth reading the other book as it does flesh out Machiavelli’s political perspective.