In regardst to The Prince, why is Machiavelli considered the first political realist?

Macchiavelli has to be considered as one of the first
political realists because he was able to tear the veil off of politics and reflect its
true nature of power.  Prior to Machiavelli, rulers and leaders were seen as agents of
the divine, and their successes and failures were attributed to the graces of God. 
Machiavelli is honest enough to argue that the successes and failures of the prince or
political leader is dependent on their judgment, or the counsel they receive from their
advisers.  Church attendance, divine revelation, and their own spiritual base are not as
important as how the leader judges their body politic and their reactions to policies
and initiatives.  The base of all Machiavelli's logic is power and how to keep and
develop it. This is the ultimate in realism.  Machiavelli is considered to be a
political realist because he argues that the political ruler is responsible for the
success or failure.  It is not the will of fate or destiny or even God.  For
Machiavelli, if one wants to use those elements to win over the support of the people,
it makes sense to do so.  Yet, in the end it is the ruler, themselves, the prince, who
is in the ultimate position to be a success or failure.  In this, he has to be seen as
the first political realist, as he changes the scope of what constitutes
ruling.