1911 Encyclopædia Britannica/Oligarchy

​OLIGARCHY (Gr. ὀλίγοι, few, ἀρχή, rule), in political philosophy, the term applied to a government exercised by a relatively small number of the members of a community. It is thus the appropriate term for what is now generally known as “aristocracy” (q.v.). The meaning of the terms has substantially altered since Plato’s day, for in the Republic “oligarchy” meant the rule of the wealthy, and “aristocracy” that of the really best people.