Niccolò Machiavelli

An excellent work that depicts premodern politics on the eve of the end of
the medieval period and the beginning of The Renaissance .

Basically: If you watched Game of Thrones or the Godfather , you know how things are. But this work is important for further analysis using historical realities from classical antiquity to Machiavelli's time , for his analysis and experience are indeed insightful into how power is obtained and maintained without ending up like say, Ned stark and Goffery.