Niccolo Machiavelli (1469-1527) was a statesman of Florence who advocated a strong central government and was generally considered to be one of the first, great political philosophers of the Renaissance period. He famously wrote The Prince, in which he focuses on the practical problems a politician faces whilst in power.
In Michael Sheas Influence, How to make the system work for you, Shea describes Machiavelli to be widely considered to be the archetypal devious diplomat who argued that the ends justified the means for some [Machiavelli] is the teacher of evil; for others he is a first-class technician, the supreme realist.
Machiavelli still holds sway today, his book The Prince is used and read by modern businessmen, politicians and world leaders in order to get ahead. He lays out pragmatic ideals on how to lead, and how to influence people and is a good read for those wishing to encourage entrepreneurial thinking.