Note: Do not rely on this information. It is very old.
Oligarchy
Oligarchy (Greek, "rule of a few") as used by Plato and Aristotle denotes the rule of a small exclusive class, who make use of their power only to promote their own interests. Oligarchy is the corrupted form corresponding to aristocracy, "rule of the best." [Government.] Most of the mediaeval Italian towns afforded at some period of their history typical examples of oligarchies.