During the rule of the tyrant Pisistratus, the forms of government began to take on the elements of democracy.
Hippias and Hipparchus, sons of Pisistratus, inherited their fathers power, butthey were considerably more despicable.
Sparta, a completely militarized and aristocratic state,established its leadership mainly by conquest, and kept its subject states understrict rule.
The unification of Attica was, however, carried on by mutual andpeaceful agreement under the leadership of Athens, and the inhabitants ofsmaller cities were given Athenian citizenship.
Between the 8th and 6thcenturies BC, Athens and Sparta became the two dominant cities of Greece.
Eachof these great states united its weaker neighbors into a league or confederacyunder its control.
During the third millennium BC a series of invasions from the northbegan.
The most prominent of the early invaders, who were called the Achaeans,had, in all probability, been forced to migrate by other invaders.
Mountain ranges anddeep valleys separated the peninsula into small economic and political units.
Constant feuding between cities and surrounding empires for political power made Greece the sight of many battles.