Sparta the modern view
In the 1960s and '70s, Greek history had largely become a laboratory within which to experiment with models for Cold War diplomacy. That this should be the case was largely due to the abiding genius of Thucydides, the great historian of fifth-century Athens. Thucydides offered a model of a bipolar world, divided between two great alliances. One, centered on Athens, stood for democracy; its subjects were allies, and it was a great sea power. Its land forces could not stand up to those of its rival, Sparta. Still, so long as it stood true to its democratic traditions, did not overreach itself, and practiced containment, a strategy pursued by its great leader, Pericles, Athens could win in the end. Unfortunately for the Athenians, after Pericles died two years into the Peloponnesian War, politicians who chose to pander to the masses rather than pursue sound foreign policy led the state to destruction. Sparta was a very different place. While Athens might claim to be "an education for all Greece," Sparta was xenophobic and militaristic, a foil to democratic Athens, a menace on the fringes, but little else.
Sparta historical significance
Following Athens in terms of historical significance was the polis of Sparta. Like Athens, little is known of the history of Sparta prior to the seventh century. It is speculated that Sparta came into being when two militaristic tribes merged their population, though the only real evidence for this is that Sparta possessed a joint hereditary kingship. In addition to the two kings, the government of Sparta was made up of an aristocratic senate consisting of 30 elders (gerousia), and a lower house, the Assembly of Warriors , whose primary function seems to be deciding when it was appropriate to declare war. There were also five state officers known as ephors who were elected yearly. These, along with the Senate, controlled life in Sparta. The kings seem to have possessed only ceremonial significance by the fifth century.
Late in the seventh century B.C the Spartans conquered the neighboring territory of Messenia, reducing the population to serfs, whom the Spartans called Helots. The need to control this extremely large subject population, more than any other factor, served to define the Spartan society. A constitution was written, attributed to the law-giver Lycurgus, and as a result Sparta was transformed into the most militaristic state in history. (For example, Sparta was alone in having a secret police force, designed to detect and crush any sign of rebellion among the helots.) All emphasis was placed on military training and preparedness rather than on political participation or the cultural and artistic elaboration of the polis. Thus Sparta was a polis that lacked the usual marks of such a community: the 5th-century historian Thucydides made a particular point of remarking that later ages, if they judged by the archaeological remains, would never guess the power and the prominence which Sparta enjoyed, since Sparta, lacked the grand temples and other public buildings that marked, e.g., its rival, Athens.
The absolute focus on military training and discipline led the Spartan hoplites to be the most feared land force in Greece. Many envied Sparta its unity and its military successes, but Sparta was generally viewed with fear and distrust, as an altogether closed and claustrophobic society. In a curious anticipation of the modern "Cold War," Sparta came to be cast as the antithesis of Athens: the closed, militaristic, xenophobic, philistine community which placed duty to the state above individual rights, as opposed to the open, cultured democracy where respect for the individual led to the flourishing of state and individual alike.
As we shall see Athens not unlike its modern and 'democratic' counterpart could be just as ruthless to other states who were not willing to go the 'democratic' way. While Sparta along with its more modern 'evil empire' equivalent was to show a more international approach to its defeated enemy when others clamored for its complete oblivion.
The Spartan state as innovator
The most radical feature of the Spartan constitution, however, was the introduction of Land Reform. Although this event is lost in the mists of undated ancient history, all ancient historians agree that at some time (probably in the late 8th or early 7th Century BC ) Spartan society underwent a severe crisis. A rebellion or civil war so threatened the continued existence of the city-state, that the citizens were prepared to accept extensive reforms, effectively a new Constitution. This Constitution, reputedly developed by Lycurgus, included a redistribution of the land. The land was divided into equal plots of sufficient size to support a man and his family, and each citizen was given a plot, or estate, a "kleros." Henceforth, the Spartans called themselves "Equals" - because they were equal not only in rights but also in wealth.
There is no question that with time this equality of wealth was eroded. Whether by inheritance, marriage or the acquisition of new lands through conquest after the Land Reform, by the second half of the 5th Century BC wealth had become concentrated in the hands of fewer and fewer families. Spartan citizens were no longer equally wealthy and were no longer able to pay their mess dues. Yet even so, the myth of equality remained powerful and laws prohibited the hoarding of wealth, even the ownership of gold and silver coins (possibly all gold and silver). The ostentatious display of wealth was frowned upon socially.
The public educational system was admired almost universally by contemporaries and praised by philosophers such as Plato and Aristotle.
Although Spartans were proud to say they built their monuments "in flesh" - meaning that the virtue and courage of its citizens were the greatest monuments any city could possess - they were not lacking in architectural and artistic achievements. Particularly, their music and dance was famous throughout the ancient world. The oldest recorded heterosexual love poem was the work of a Spartan poet praising Spartan maidens.
Sparta was eclipsed by the rise of Athens, a city with roughly 5-times the number of citizens and, following the defeat of Persia in the early 5th Century, an Empire. Sparta's once revolutionary and innovative institutions became calcified. Its artistic achievements stagnated as the population declined, its citizens now increasingly sent abroad as governors or advisors freed from the restraints of home, unused to wealth and money became arrogant and venial. The demands of power following Sparta's victory in the Peloponnesian Wars grew and with it the military commitments, which in its turn demanded more money for the increasing use of mercenaries as the population declined. Nevertheless the decline of Sparta starting from the mid 5th Century BC should not entirely obscure its earlier accomplishments.