Niccolò Machiavelli entered Florentine public service in 1498 as secretary of the republic's second chancery. Over fourteen years he undertook diplomatic missions, prepared reports, and dealt with military and administrative affairs. Encounters with rulers and commanders, including Cesare Borgia, informed his study of how power was acquired and maintained. He supported a citizen militia as an alternative to dependence on mercenary soldiers, but its defeat formed part of the republic's collapse in 1512.

The returning Medici dismissed Machiavelli. Suspected of involvement in a conspiracy in 1513, he was imprisoned and tortured before being released. Living outside Florence, he turned increasingly to writing while seeking a route back into public service. The Prince, largely composed in 1513, examined the difficulties of acquiring and preserving princely rule. It considered military force, reputation, political necessity, and the interaction of opportunity with a ruler's capacities. Its frank discussion of actions conventionally condemned by morality helped make his name controversial.

The Discourses on Livy explored republican institutions, conflict, liberty, and the preservation of political communities through readings of Roman history. The differences between that work and The Prince have generated competing interpretations of his purposes. Reducing his thought to a simple recommendation of dishonesty obscures his concern with institutions, civic strength, historical judgment, and the fragility of political arrangements.

Machiavelli also wrote poetry, letters, and dramatic works. His comedy Mandragola used deception and desire to expose the behavior of recognizable social types. The Art of War, published in 1521, presented military questions in dialogue form and continued his criticism of mercenary dependence. A commission under Medici patronage enabled him to write the Florentine Histories, which he presented to Pope Clement VII in 1525. Limited later employment never restored the sustained political authority of his republican years.

When the Medici were expelled again in 1527, Machiavelli did not recover his former office. He died that June, and major political works including The Prince were published posthumously. His career combined practical diplomacy and military organization with historical and literary inquiry. Disputes around his writing concern political coercion and the conditions under which communities might preserve freedom.