Niccolo Machiavelli's The Prince

The Prince (Italian: Il Principe) is a political treatise by the Italian diplomat, historian and political theorist Niccolò Machiavelli. 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.

Niccolò di Bernardo dei Machiavelli
(3 May 1469 – 21 June 1527) was an Italian historian, diplomat, philosopher, humanist and writer based in Florence during the Renaissance. A founder of modern political science, he was a civil servant of the Florentine Republic. He also wrote comedies, carnival songs, and poetry. His personal correspondence is renowned in the Italian language. He was Secretary to the Second Chancery of the Republic of Florence from 1498 to 1512, when the Medici were out of power. He wrote his masterpiece, The Prince, after the Medici had recovered power and he no longer held a position of responsibility in Florence.
-Wikipedia.com