The Prince

The Prince is sometimes claimed to be one of the first works of modern philosophy, especially modern political philosophy, in which the effective truth is taken to be more important than any abstract ideal. It was also in direct conflict with the dominant Catholic and scholastic doctrines of the time concerning how to consider politics and ethics.
Although it is relatively short, the treatise is the most remembered of his works and the one most responsible for bringing the word "Machiavellian" into wide usage as a pejorative term. It also helped make "Old Nick" an English term for the devil, and even contributed to the modern negative connotations of the words "politics" and "politician" in western countries. In terms of subject matter it overlaps with the much longer Discourses on Livy, which was written a few years later.