The period of the ancient Greek history between the 11th and 8th century. BC is known as Geometric period, and took it's name from the geometric shapes at the decoration of the vases. A few years ago was characterized as the "Dark Ages", because the facts for this period were very poor, and often was placed in prehistory.

The decline fall and dissolution of the Mycenean kingdoms after the middle of the 12th century B.C. was followed by a period of approximately four centuries, during which a new framework was created and a new era was introduced for Greek culture and history.

The main characteristic of this period was the extensive drift and migration both to the inland of mainland Greece, and to the Aegean islands and the coast of Asia Minor. Greek peoples that previously inhabited mountainous and barren areas in the periphery of the Mycenean world now moved toward the formerly prosperous, productive and fertile Mycenean centers, which they took over, opening  the way for the creation of the ancient Greek city-states in the next period.

At the end of the Mycenaean period, the first peoples were moved from the northwest- according to Herodotus and Thucydides-, settled in areas which took their name.

Dorians and Aetolians from Central Greece moved to the Peloponnese, while Boeotians from Central Thessaly moved southward and settled in the area SE of Mt. Parnassus. Ionians from the Northern coast of the Peloponnese moved to the Saronic Gulf and Attica and from there to Euboea. From the mountainous region of Mt. Pindos, the Thessalians settled in Thessaly and the Magnesians in the area of Mt. Pelion.

At the same time, the former inhabitants of these areas, which were gradually pushed back by the new peoples, moved toward the islands, the coast of Asia Minor and Cyprus. Ionians from Attica and Euboea emigrated to the Cyclades and Ionia, namely Samos, Chios and the opposite coast, from Phokaia to Miletos. Aeolian-speaking inhabitants of Thessaly settled in Lesbos, Tenedos and the opposite coast. Dorians from the Peloponnese emigrated to Crete and the SE coast of Asia Minor, while Achaeans and Arcadians, also from the Peloponnese, moved to Crete, Pamphylia and Cyprus.

According to the main viewpoint, when the Mycenaean states showed signs of weakness, the Dorians, who lived then in northwestern Greece, and under the pressure from other people who came from the north, moved to the south. It was a large-scale military operation which resulted in Central Greece and Peloponnese.

According to a newer position, historically proved, the Dorians-a Greek pastoral race which were resident in mountainous regions of Greece took advantage of the decline of Mycenae to be moved to lowland areas. Relative with the Doric settlement in the Peloponnese was a later myth for the return of Heraklides, the descendents of Herakles who had been expelled once. The causes of the first migratory period which led the first large movements in Greece focus on the population growth which occurred in the Homeric communities at the end of the 9th century BC.

Certainly, the Homeric communities while were keeping the character of the closed rural economy based on limited arable land, due to lack of skills and resources from other areas, and the concentration of the land in few hands, were unable to face the new economic needs. Solution to the crisis offered the imperialistic wars, the establishment of colonies and a new development model, based in the promotion of the small industry and trading.

Until the 8th century B.C., the extensive migratory movement had almost taken on its final form. Thereafter only new cities and colonies were formed. The growth of commercial activity and the quest for new lands resulted in the establishment in the 8th century B.C. of the first colonies in the West by Euboeans, Megarians and Spartans.

All the above movements, which took place gradually, resulted in political decentralization and led to the formation of a number of small autonomous phyletic states. In the 8th century the first city-states were formed; the city state was to become the basic component of Greek society in the historical period, within which emerged the ideas and notions of the panhellenic nationalism as well as the national and individual liberty, which later on led to the birth of Democracy.

The Greek nation developed new, stronger bonds. The worship of several gods became common for all Greeks, the Olympian Pantheon was created and Homer and Hesiod shaped Greek mythology. In 776 B.C. the Olympic Games were established, and became the basis for the dating of all historical events until the end of antiquity.
In the 8th century B.C., the name Hellenes was established as the common identifying name of groups which inhabited Greek lands and had common characteristics, customs and descent. Those groups spoke a common language, Greek, which now began to be recorded according to a new system of writing that was borrowed from the Phoenicians and adapted to meet the needs of the Greek language.

As a nation with cohesion, the Greeks were now ready to rule over the Mediterranean, establishing important commercial harbors and colonies from the Black Sea to the Northern coast of Africa and from Asia Minor and Cyprus to the coast of France and Spain.
The colonists gained prosperity, became great seafarers and, retaining their close bonds with their mother cities, disseminated Greek civilisation to the ends of the then known world.