Everyone's heard of The Prince, and the adjective "Machiavellian" has become a regular part of the English language. It was illuminating to re-read the text and the critical essays contained in the Norton Critical Edition. The essays helped place the text within the context of the discourse up to the time of Machiavelli's writing, in which long treatments of statesmanship were centred around abstract and unrealistic exhortations to virtue. The reason The Prince became so (in)famous was because it broke with that tradition and explicitly set morality aside in order to act as a practical primer on how a ruler could stay in power given the ever-changing currents of war, diplomacy, and popular unrest around him or her. Perhaps the most interesting thing I learned was that, despite the assistance he may have provided to would-be tyrants and dictators, Machiavelli lived in the republican city-state of Florence and was a strong believer in the benefits of the republican form of government over monarchies and other types of government that he had first-hand experience with as a professional diplomat. On the other side, the great admiration that Machiavelli had for the diabolical Cesare Borgia is a testament that he really believed in what he wrote. I wished the edition had a better essay summarizing Machiavelli's life and detailing what led to his torture and retirement from public life.
[Note that the second edition is pictured here, but I have the first edition]