Niccolo Machiavelli (1469-1527) was born in Florence, and became an infamous author and politician. His most influential work was The Prince. The book was both influential and reviled, but established the basic concepts of 'realpolitik'.
Macchiaveli entered the Florentine government as a secretary and quickly rose to prominence working diplomatic posts. The overthrow of the Florentine Republic by the Medici however saw him lose his status. Macchiaveli tried to curry favour with the Medici by writing The Prince. In the end the public outcry against this book did him more harm than good, and Macchiaveli was never to be involved directly in politics again.