The book talks about politics and government. During his life, Machiavelli saw many changes in the government of Florence. He thought a lot about what a king or prince should do to make a strong government. In the book, he said the ruler had to get a lot of power.
Some people think that Machiavelli was being honest with his advice and saying what he really thought. Other people think that Machiavelli was playing a joke on princes who wanted too much power and did not care about what was right.