The Prince (II Principe) is a book on politics and political philosophy by Italian theorist Niccolò Machiavelli. The book was presented as a treatise advising Florentine leader Lorenzo de Medici ("the Magnificent"). In The Prince, Machiavelli expounded his theories on how to govern and maintain a monarchical state, or "principality". He touched on each kind of such state and gave remark on its strength and weakness, as well as solution to its problems. The work is often seen as advocating amoral pursuit of political expediency and unscrupulous maintenance of power, and led to coining of the adjective Machiavellian for shrewd and malicious practice in politics. In the end of the book, Machiavelli expressed his longing for an emancipator who could unify the scattered territories of Italy.
One of the first prince extensively commented in the book is Louis XII, King of France, who conquered the state of Milan twice but subsequently lost it. According to Machiavelli, Louis' failure was due to several of his strategic errors: inviting a powerful foreigner, Spain, into the region, allowing Pope Alexander VI, the pope notorious for his secularism and corruption, to become more powerful, and refusal to live in Italy or to colonize Italy. In the course of dissecting the cast study of Louis, he concluded that to maintain a newly acquired state, a ruler must not make any neighboring state stronger, either by helping the weaker states or other means, must not bring a powerful foreign entity into the region, and must live in the acquired state or send colonies, if the state spoke a different language than the ruler's own state.
In Chapter IV, Machiavelli proposed the question that how Alexander the Great could easily maintain the occupied area of Persia. He contrasted two different states, one, like Persia and Turkey, that had a centralized authority with appointed local bureaucrats, and states like France, which had provincial hereditary nobles. He asserted that the latter one was easier to be conquered while hard to maintain, while it was difficult to annex the former but easy to keep the occupation.
One of the princes he admired was Cesare Borgia, the son of Alexander VI. He thought that Cesare could have brought about the unification of Italy if not for "ill fortune".
Frederick the Great, King of Prussia who was known for espousing the principles of The Enlightenment era, wrote an essay titled Anti-Machiavel to refute arguments presented by Machiavelli that a ruler must only be concerned by maintaining political authority.