There are two types of states: republics and principalities. Machiavelli declares that he will not discuss republics, examining only how principalities may be acquired and governed. Principalities are inherited or new.
New principalities are either annexed to a ruler's existing territory or are completely new. New principalities are either used to being ruled by a prince or are used to being free. New principalities are acquired by luck or by strength.
Hereditary principalities, which are used to being ruled by the prince's family, are easy to maintain, because tradition keeps the prince's position stable as long as he does not make himself hated.
In Chapter 1, Machiavelli traces the basic outlines of a discussion that will take him through Chapter 11: the different types of states, how to acquire them, and the difficulties they present to a ruler. Machiavelli refers to republics, which are governed by their citizens, and principalities or princely states, which are governed by a single, strong ruler (a prince). Because he is addressing one of those princes, he avoids any discussion of republican government, except to note that republics conquered by a new prince are used to living free, a theme he returns to in later chapters. In many of his other works, Machiavelli passionately defended republican forms of government, and he suffered for his defense of the Florentine republic which the Medici now ruled.
Hereditary principalities are those in which rule is passed down among members of one family. Machiavelli considers these the easiest to govern and therefore disposes of the subject by observing that any minimally competent prince can hold onto one. At the end of Chapter 2, Machiavelli makes the first of his many observations about human nature, noting that people are inclined to forget that even old established governments were innovations once.
Milan/Sforza Francesco Sforza (1401-1466) became Duke of Milan in 1450. (See the List of Characters.)
Naples/King of Spain Ferdinand (1452-1516) had originally agreed to divide the Italian kingdom of Naples with Louis XII of France, but Ferdinand drove out the French forces and took over Naples in 1503.
Duke of Ferrara actually two dukes, Ercole d'Este (1431-1505), who lost territory to the Venetians in 1484, and his successor, Alfonso d'Este (1476-1534), who managed to stay in power despite the opposition of three different popes. The d'Este family had ruled Ferrara for almost four centuries.