Machiavelli was one of the most influential writers during the Renaissance. He wrote about many topics but he was well-known for writing "The Prince".
He was a military official of the Florentine government when the Medici family out of power. When Medici was back in power, Machiavelli was imprisoned and tortured. When he got his freedom, he wrote his masterpiece. His writing referred to a "new prince " who might rule in place of the Medici, this was a calculating prince.
This book became one of the most influential books in history. The term Machiavellian is used to refer to a conduct associated to ambition, deceit and brute force.