The single greatest political innovation of the ancient Greeks was the establishment of the polis, or "city-state". In the Mycenean age, the Greeks lived in small, war-oriented kingdoms, but for reasons unknown to us, they abandoned their cities and their kingdoms sometime between 1200 and 1100 BC. From that point onwards, they lived in either sedentary or nomadic tribal groups; the period is called the Greek Dark Ages and lasted until sometime between 800 and 700 BC. The tribal or clan units of the dark ages slowly grew into larger political units at the end of this period; beginning around 800 BC, trade began to dramatically accelerate between the peoples of Greece. Marketplaces grew up in Greek villages and communities began to gather together into large defensive units, building fortifications to use in common. On this foundation, the Greek-speaking people who lived on the Greek peninsula, the mainland, and the coast of Asia Minor, developed political units that were centrally based on a single city . These city-states were independent states that controlled a limited amount of territory surrounding the state. The largest of these city-states, for instance, was Sparta, which controlled more than 3000 square miles of surrounding territory.
The overwhelming characteristic of the city-state was its small size; this allowed for a certain amount of experimentation in its political structure. The age of the city-state in Greece is an age of dynamic and continual experimentation with political structures; this period of experimentation gave the European world most of its available political structures. Its small size also allowed for democracy, since individual city-states were small enough that the free male citizens constituted a body small enough to make policy decisions relatively efficiently. The overwhelming importance of the polis in the evolution of European political structures is betrayed by the word "political" itself: derived from the word polis , "political" etymologically means "of or relating to the polis ."
Politically, all the Greek city-states began as monarchies. In their earliest stages, they were ruled by a basileus , or hereditary king. The Greeks living in those city-states, however, soon tired of the kings, many of which were overthrown in the eighth century BC. A variety of political alternatives were experimented with in place of the basileus : these included oligarchy, timocracy, tyranny, and democracy.
The most common form of government in the Greek city-states was oligarchy, or "rule by a few." The oligarchs were almost always drawn from the noble classes or from the wealthiest citizens of the state ("rule by the wealthy" is called a timocracy), but a variety of oligarchic forms were invented in the eighth century. These include having the members of the oligarchy chosen by lot, having them elected, or rotating the oligarchy among members of a certain class. The oligarchs most often ruled absolutely; they had many of the powers granted to a king. However, many oligarchies ruled in conjunction with other political structures: in Sparta, for instance, the oligarchy ruled over and with a pair of kings, a council, and a democratic assembly. The reforms of Solon in Athens left in oligarchy of nobles in charge of the state, but granted enormous powers to an elected, democratic Assembly. Even though the powers of the oligarchs were diffused among a group (which could be surprisingly large), the power of the oligarchy could be remarkably totalitarian, since many of the members of the oligarchy were drawn from the same class and had the same interests. Many of the early oligarchic governments and a few of the kings were overthrown by "tyrants" (in Greek, tyrranos); oligarchy could be a particularly unstable form of government when it was also a timocracy, or "rule by the wealthy." While Greek history is generally unkind to the tyrants, we can through the haze of later Greek propaganda come to some dispassionate conclusions about the nature of the tyrranies. The Greeks believed that the tyrants were illegitimate usurpers of political power; they seem, however, to have had in many cases popular support. The Greek tyrants were often swept into power by dissatisfaction or crisis; they were more often then not extremely popular leaders when they assumed the tyrrany. They often assumed absolute control in the name of reforming the government; Solon, the great reformer of the Athenian consitution, was essentially granted all the powers of a tyrant. Many of the tyrants, in fact, were brilliant and morally sound reformers and activists; many, however, were not. Once in power, they ruled as a king would rule, and many attempted, and some succeeded, to make the tyrrany hereditary—in essence, a form of monarchy. Many of them seem to have directed their attentions to the crisis that swept them into office, but most of them set about shoring up their shaky hold on power. For the tyrants ruled only by a thread; they maintained power only by their hold on military force and often fear. The tyrranies were by nature highly unstable, and they fell apart rapidly. Even so, tyrrany was a widespread political institution throughout the Greek-speaking world: tyrranies were experimented with not only in Greece, but Asia Minor and even as far away as the Greek cities in Sicily.
By the sixth century, the experiments began to settle around two alternatives. The tyrranies never died out, but oligarchy became the settled norm of the Greek city-states. Several of these oligarchies, however, were replaced by a second alternative that originated sometime in the sixth century: democracy. The word means, "rule by the demos (people)," but the Greek democracies looked nothing like modern democracies. First, they really do mean rule by the people ; the Greek democracies were not representative governments, they were governments run by the free, male citizens of the city-state. Second, all the members of a city-state were not involved in the government: slaves, foreigners, and women were all disbarred from the democracy. So, in reality, the democratic city-states more closely resembled oligarchies for a minority ruled the state—it was a very large minority, to be sure, but still a minority.
One further innovation should be remarked upon: naturalization. The Greek city-states determined citizenship by descent. Although we tend to gloss over this aspect of Greek society, the Greeks still had a fundamental and working sense of kinship relationships and tribal organization. An Athenian, Spartan, or Corinthian citiizen would have been well-versed in their kinship and tribal affiliations, so citizenship was based on descent . Most cities demanded that its citizens be able to demonstrate descent from one parent who was a citizen; but often the requirements were more difficult, demanding that the each citizen demonstrate that both parents were Athenian citizens. Every once in a while, however, the administration of a polis would admit people into the citizenship who could not demonstrate descent from a citizen, that is, the polis allowed for naturalization. This was a brand new concept in the ancient world, and contributed to the Greek sense during the Hellenistic Age that Greek culture was or could be a universal culture.