In the ancient world Greece was not a unified country, there was no nation of Greece . In this web site when we say ' Persia invaded Greece ' it is not like saying ' Russia invaded the USA '. There is not any unified nation rather Greece consisted of a collection of independent city-states or polis', with a wide variety of governments.
In the modern view the city-states were quite small, a large city-state might have 20,000 citizens, so they can be seen as cities, but they were independent of each other and self-governing and in that regard they were states.
From one polis to another the government could vary widely. Athens in the 5th century was a democracy, other city-states were monarchies, oligarchies, or other forms of government. There was no political unity from one city-state to another; there was not even any coherency of political form.
A quick example between two of the leading city-states:
|Sparta - Oligarchy
||Athens - Democracy
||voting members of society
The citizens of the various polis' did recognise a cultural link between themselves as Greeks or Hellenes and non-Greeks or barbarians or a better word to use would be foreigners. The cultural link was most obvious as the Greek city-states all spoke Greek. Also, they worshipped the same gods and overall the same manner though each polis had it's own festivals that were unique to it, they still shared the same religious practices and shared the same religious shrines such as the Apollo's shrine of Delphi and the Zeus' shrine of Dadona.
The cultural link between the Greek city-states did not preclude hostilities and rivalry between themselves. It was not uncommon for one polis to go to war with another polis, none more famous than the Peloponnesian War.
There was no nation of Greece during the Persian wars and no politicalised leadership infact the Hellenic world was not even geographically similar to what we today consider Greece . There were Greek city-states scattered throughout the Mediterranean including Sicily, Turkey and around the Black Sea.
The polis system probably developed in the 8th century, but without surviving documentation this is only a guess made by today's scholars.
Ancient Greece - definition
c70,000 B.C.: Human inhabitants , being food gatherers, who used up the supplies of animals, fish or wild fruit in one district and moved on to another.
c6,000 B.C.: Marks the beginning of sedentary life and of political organisation. Such condition made possible further material improvements, such as the introduction of pottery.
c3,000 B.C.: The beginning of the bronze age, this did not mark any major cultural change.
c2,000 B.C.: Invaders coming from the north destroyed most of the previous settlements; they brought in a new type of pottery and a distinctive plan for building dwellings. It is probably that the invaders were the first speakers of Greek to settle in Greece.
c1600 - c1100 B.C.: Greece is very much influenced by the Minoan civilization with a luxurious and martial culture. Most of the towns were clustering round elaborate palaces, which directed the economy.
c1100 B.C.: A series of migration and invasion begins, effecting the Near East, Asia Minor and Greece. Little is known about the 'invaders', and they may have drawn recruits from among the settled populations, which they subverted. Accordingly , it is convenient to call them "land and sea-raiders", a term based on Egyptian documentation. The upper layers of palace bureaucracies were removed, the art of writing was lost, and there was no further building in stone in Greece until the later 7th and 8th century.
The migration lasted a long time and carried different groups of people in different directions. Later Greek tradition called the invaders Dorian Greeks, and said that their home just before the migrations was in the border district between Epirus and Thessaly.
A legend said that the Dorians who came to the Peloponnese were led by the descendants of Hercules, a mythical hero, and so the migration into the Peloponnese was called 'the return of the Heracleidae".
With all the upheaval going on, the Greek language had a multiplicity of dialect from canton to canton , but generally fell into two major division. We will call them East Greek and West Greek.
East Greek: Was descended from the type of Greek which was first brought into Greece around 2,000 B.C. the subdivision of these included Aeolian, Ionian and Arcadia-Cyprian. In the Peloponnese they were confined to Arcadia, the mountainous center, which had a dialect akin to that spoken in Cyprus.
West Greek: Came with the Dorians and was also spoken in North-West Greece. This suggests that the tradition that the Dorians came from between Epirus and Thessaly, is probably right. Later on the Dorians going via sea, occupied Crete, the islands of Melos and Thera and then Rhodes, Kos and some sites on the Asiatic mainland.