The isonomic and isegoric democracy was first organized into about 130 ’’demes’’, which became the foundational civic element. The 10,000 citizens exercised their power via the assembly (the ecclesia, in Greek) of which they all were part, headed by a council of 500 citizens chosen at random.
The city's administrative geography was reworked, the goal being to have mixed political groups--not federated by local interests linked to the sea, to the city, or to farming--whose decisions (declaration of war, etc.) would depend on their geographical situation. Also, the territory of the city was divided into thirty ’’trittyes’’ as follows:
A tribe consisted of 3 trittyes, taken at random, one from each of the three groups. Each tribe therefore always acted in the interest of all 3 sectors.
This is this corpus of reforms that would in the end allow the emergence of a wider democracy in the 460s and 450s BC.
In Ionia (the modern Aegean coast of Turkey), the Greek cities, which included great centres such as Miletus and Halicarnassus, were unable to maintain their independence and came under the rule of the Persian Empire in the mid 6th century BC. In 499 BC that region’s Greeks rose in the Ionian Revolt, and Athens and some other Greek cities went to their aid, though they were at first quickly forced to back down after defeat in 494 BC at the battle of Lade. Asia Minor returned to Persian control.
In 492 BC, the Persian general, Mardonius led a campaign through Thrace and Macedonia and while victorious, he was wounded and forced to retreat back into Asia Minor. In addition, the naval fleet of around 1,200 ships which accompanied Mardonius on the expedition was wrecked by a storm off the coast of Mount Athos. Later, the generals Artaphernes and Datis launched a naval assault on the Aegean islands, causing them to submit, then attempted a landing at Marathon in 490 to take Athens. In 490 BC, Darius the Great, having suppressed the Ionian cities, sent a fleet to punish the Greeks. 100,000 Persians (historians are uncertain about the number; it varies from 18,000 to 100,000) landed in Attica intending to take Athens, but were defeated at the Battle of Marathon by a Greek army of 9,000 Athenian hoplites and 1,000 Plateans led by the Athenian general Miltiades. The burial mound of the Athenian dead can still be seen at Marathon. The Persian fleet continued to Athens but, seeing it garrisoned, decided not to attempt an assault.
Ten years later, in 480 BC, Darius' successor Xerxes I sent a much more powerful force of 300,000 by land, with 1,207 ships in support, across a double pontoon bridge over the Hellespont. This army took Thrace, before descending on Thessaly and Boetia, whilst the Persian navy skirted the coast and resupplied the ground troops. The Greek fleet, meanwhile, dashed to block Cape Artemision. After being delayed by the Spartan King Leonidas I at Thermopylae, Xerxes advanced into Attica, where he captured and burned Athens. But the Athenians had evacuated the city by sea, and under Themistocles they defeated the Persian fleet at the Battle of Salamis. During peacetime in 483, a vein of silver ore had been discovered in the Laurion (a small mountain range near athens), and the hundreds of talents mined there had paid for the construction of 200 warships to combat Aeginetan piracy. A year later, the Greeks, under the Spartan Pausanius, defeated the Persian army at Plataea.
The Athenian fleet then turned to chasing the Persians from the Aegean Sea, defeating their fleet decisively in the battle of Cape Mycale; then in 478 BC the fleet captured Byzantium. In the course of doing so Athens enrolled all the island states and some mainland ones into an alliance called the Delian League, so named because its treasury was kept on the sacred island of Delos. The Spartans, although they had taken part in the war, withdrew into isolation afterward, allowing Athens to establish unchallenged naval and commercial power.
The Persian Wars ushered in a century of Athenian dominance in Greek affairs. Athens was the unchallenged master of the sea, and also the leading commercial power, although Corinth remained a serious rival. The leading statesman of this time was Pericles, who used the tribute paid by the members of the Delian League to build the Parthenon and other great monuments of classical Athens. By the mid 5th century the League had become an Athenian Empire, as demonstrated by the transfer of the League's treasury from Delos to the Parthenon in 454 BC.
The wealth of Athens attracted talented people from all over Greece, and also created a wealthy leisure class who became patrons of the arts. The Athenian state sponsored learning and the arts, particularly architecture. Athens became the centre of Greek literature, philosophy (see Greek philosophy), and the arts (see Greek theatre). Some of the greatest figures of Western cultural and intellectual history lived in Athens during this period: the dramatists Aeschylus, Aristophanes, Euripides, and Sophocles; the philosophers Aristotle, Plato, and Socrates; the historians Herodotus, Thucydides, and Xenophon; the poet Simonides; and the sculptor Pheidias. The city became, in Pericles' words, "the school of Hellas".
The other Greek states at first accepted Athenian leadership in the continuing war against the Persians, but after the fall of the conservative politician Cimon in 461 BC, Athens became increasingly open in its imperialist ambitions. After the Greek victory at the Battle of the Eurymedon in 466 BC, the Persians were no longer a threat, and some states, such as Naxos, tried to secede from the League, but were forced to remain members. The new Athenian leaders, Pericles and Ephialtes, let relations between Athens and Sparta deteriorate, and in 458 BC war broke out. After some years of inconclusive war, a 30-year peace was signed between the Delian League and the Peloponnesian League (Sparta and her allies). This coincided with the last battle between the Greeks and the Persians, a sea battle off Salamis in Cyprus, followed by the Peace of Callias (450 BC) between the Greeks and Persians.
In 431 BC war broke out again between Athens and Sparta and its allies. The immediate causes of the Peloponnesian War vary from account to account. However three causes are fairly consistent among the ancient historians, namely Thucydides and Plutarch. Prior to the war, Corinth and one of its colonies, Corcyra (modern-day Corfu), got into a dispute in which Athens intervened. Soon after, Corinth and Athens argued over control of Potidaea (near modern-day Nea Potidaia), eventually leading to an Athenian siege of Potidaea. Finally, Athens issued the "Megarian Decrees", a series of economic decrees that placed economic sanctions on the Megarian people. Athens was accused by the Peloponnesian allies of violating the Thirty Years Peace through all of the aforementioned actions, and Sparta formally declared war on Athens.
It should be noted that many historians consider these to be merely the immediate causes of the war. They would argue that the underlying cause was the growing resentment on the part of Sparta and its allies at the dominance of Athens over Greek affairs. The war lasted 27 years, partly because Athens (a naval power) and Sparta (a land-based military power) found it difficult to come to grips with each other.
Sparta's initial strategy was to invade Attica, but the Athenians were able to retreat behind their walls. An outbreak of plague in the city during the siege caused heavy losses, including that of Pericles. At the same time the Athenian fleet landed troops in the Peloponnese, winning battles at Naupactus (429 BC) and Pylos (425 BC). But these tactics could bring neither side a decisive victory. After several years of inconclusive campaigning, the moderate Athenian leader Nicias concluded the Peace of Nicias (421 BC).
In 418 BC, however, hostility between Sparta and the Athenian ally Argos led to a resumption of hostilities. At Mantinea Sparta defeated the combined armies of Athens and her allies. The new fighting brought the military party, led by Alcibiades, back to power in Athens. In 415 BC Alcibiades persuaded the Athenian Assembly to launch a major expedition against Syracuse, a Peloponnesian ally in Sicily. Though Nicias was a skeptic about the Sicilian Expedition, he was appointed along with Alcibiades to lead the expedition. Due to accusations against him, Alcibiades fled to Sparta where he persuaded Sparta to send aid to Syracuse. As a result, the expedition was a complete disaster and the entire expeditionary force was lost. Nicias was executed by his captors.
Sparta had now built a fleet (with the help of the Persians) to challenge Athenian naval supremacy, and had found a brilliant military leader in Lysander, who seized the strategic initiative by occupying the Hellespont, the source of Athens' grain imports. Threatened with starvation, Athens sent its last remaining fleet to confront Lysander, who decisively defeated them at Aegospotami (405 BC). The loss of her fleet threatened Athens with bankruptcy. In 404 BC Athens sued for peace, and Sparta dictated a predictably stern settlement: Athens lost her city walls, her fleet, and all of her overseas possessions. Lysander abolished the democracy and appointed in its place a council of thirty to govern Athens.
Then the Theban generals Epaminondas and Pelopidas won a decisive victory at Leuctra (371 BC). The result of this battle was the end of Spartan supremacy and the establishment of Theban dominance, but Athens herself recovered much of her former power because the supremacy of Thebes was short-lived. With the death of Epaminondas at Mantinea (362 BC) the city lost its greatest leader and his successors blundered into an ineffectual ten-year war with Phocis. In 346 BC the Thebans appealed to Philip II of Macedon to help them against the Phocians, thus drawing Macedon into Greek affairs for the first time.
The Peloponnesian War was a radical turning point for the Greek world. Before 403 BC, the situation was more defined, with Athens and its allies (a zone of domination and stability, with a number of island cities benefiting from Athens’ maritime protection), and other states outside this Athenian Empire. The sources denounce this Athenian supremacy (or hegemony) as smothering and disadvantageous.
After 403 BC, things became more complicated, with a number of cities trying to create similar empires over others, all of which proved short-lived. The first of these turnarounds was managed by Athens as early as 390 BC, allowing it to re-establish itself as a major power without regaining its former glory.
Sparta refused to see Lysander or his successors dominate. Not wanting to establish a hegemony, they decided after 403 BC not to support the directives that he had set up.
Agesilas came to power by accident at the start of the 4th century BC. This accidental accession meant that, unlike the other Spartan kings, he had the advantage of a Spartan education. The Spartans at this date discovered a conspiracy against the laws of the city conducted by Cinadon and as a result concluded there were too many dangerous worldly elements at work in the Spartan state.
Agesilas employed a political dynamic that played on a feeling of pan-Hellenic sentiment, launching a successful campaign against the Persian empire. However, the Persian empire reacted and - with access to Persian gold - changed from backing Sparta to backing the Athenians, who used Persian subsidies to rebuild their walls (destroyed in 404 BC) as well as to reconstruct their fleet and win a number of victories, notably at Cnidus.
In 394, the Spartan authorities decided to force Agesilas to return to mainland Greece. For six years, Sparta fought Corinth, with Corinth partly drawing on Athenian support. This war had descended into guerilla tactics and Sparta decided that it could not fight on two fronts and so chose to ally with Persia.
In the 370s, Sparta fought Thebes. Athens came to mistrust the growing Theban power, particularly due to Thebes’ razing in 375 BC of the city of Platea, and so negotiated an alliance with Sparta against Thebes in 375 BC. In 371, however, Sparta suffered a bloody defeat at Leuctra, losing a large part of its army and 400 of its 2,000 citizen-troops. Sparta’s hegemony was over, replaced by that of Athens.
The Athenians had to make their own contribution to the alliance, the eisphora. They reformed how this tax was paid, creating a system in advance, the Proseiphora, in which the richest individuals had to pay the whole sum of the tax then be reimbursed by other contributors. This system was quickly assimilated into a liturgy.
The main reasons for the eventual failure were structural. This alliance was only valued out of fear of Sparta, which evaporated after Sparta's fall in 371 BC, losing the alliance its sole raison d'etre. The Athenians no longer had the means the fulfil their ambitions, and found it difficult merely to finance their own navy, let alone that of an entire alliance, and so could not properly defend their allies. Thus, the tyrant of Pherae was able to destroy a number of cities with impunity. From 360, Athens lost its reputation for invincibility and a number of allies (such as Byzantium and Naxos in 364) decided to secede.
In 357 BC the revolt against the league spread, and between 357 and 355, Athens had to face war against its allies, a war whose issue was marked by a decisive intervention by the king of Persia in the form of an ultimatum to Athens, demanding that Athens recognise its allies' independence under penalty of Persia's sending 200 triremes against Athens. Athens had to renounce the war and leave the confederacy to weaken itself more and more. The Athenians had failed in all their plans and were unable to propose a durable alliance.
That confederacy is well known to us from a papyrus found at Oxyrhyncus and known as "The Anonyme of Thebes". Thebes headed it and set up a system under which charges were divided up between the different cities of the confederacy. Citizenship was defined according to wealth, and Thebes counted 11,000 active citizens.
It was divided up into 11 districts, each providing a federal magistrate called a "Boeotarch", a certain number of council members, 1,000 hoplites and 100 horsemen. From the 5th century BC the alliance could field an infantry force of 11,000 men, in addition to an elite corps and a light infantry numbering 10,000; but its real power derived from its cavalry force of 1,100, commanded by a federal magistrate independent of local commanders. It also had a small fleet which played a part in the Peloponnesian War by providing 25 triremes for the Spartans At the end of the conflict, the fleet consisted of 50 triremes and was commanded by a "navarch".
All this constituted a significant enough force that the Spartans were happy to see the Boeotian confederacy dissolved by the king's peace. This dissolution, however, did not last, and in the 370s there was nothing to stop the Thebans (who had lost the Cadmea to Sparta in 382 BC) from reforming this confederacy.
He decided in the end to constitute small confederacies all round the Peloponnessus, forming an Arcadian confederacy (The king's peace had destroyed a previous Arcadian confederacy and put Messene under Spartan control.)
Sparta remained an important power and some cities continued to turn against her. The confederal framework was an artificial one, since it attempted to bring together cities that had never been able to agree. Such was the case with the cities of Tegea and Mantinea, which re-allied in the Arcardian confederacy. The Mantineans received the support of the Athenians and the Tegeans that of the Thebans. The Thebans prevailed, but this triumph was short-lived, for Epaminondas died in the battle, stating that "I bequeath to Thebes two daughters, the victory of Leuctra and the victory at Mantinea".
In the end, the Thebans abandoned their policy of intervention in the Peloponnesus. Xenophon thus concludes his history of the Greek world in 362 BC.
The end of this period was even more confused than its beginning. Greece had failed and, according to Xenophon, the history of the Greek world was no longer intelligible.
The idea of hegemony disappeared. From 362 BC onward, there was no longer a single city that could exert hegemonic power - the Spartans were greatly weakened; the Athenians were in no condition to operate their navy, and after 365 no longer had any allies; Thebes could only exert an ephemeral dominance, and had the means to defeat Sparta and Athens but not to be a major power in Asia Minor.
Other forces also intervened, such as the Persian king, who was appointed as arbitrator between the Greek cities by the cities themselves. This situation reinforced the conflicts and there was a proliferation of civil wars, with the confederal framework a repeated trigger for wars. One war led to another, each longer and more bloody, and the cycle could not be broken. Hostilities even took place during winter for the first time, with the 370 invasion of Laconia.
Under Philip II, (359–336 BC), Macedon expanded into the territory of the Paionians, Thracians, and Illyrians. The Macedonians became more politically involved with the south-central city-states of Greece, but also retained more archaic aspects harking back to the palace culture, first at Aegae (modern Vergina) then at Pella, resembling Mycenaean culture more than that of the classical city-states.
Philip's son Alexander the Great (356–323 BC) managed to briefly extend Macedonian power not only over the central Greek city-states, but also to the Persian empire, including Egypt and lands as far east as the fringes of India.
The classical period conventionally ends at the death of Alexander in 323 BC and the fragmentation of his empire, divided among the Diadochi.