In 431, the Spartans and Athenians went to war. Both sides thought they were ready, but soon discovered that they were wrong. The Spartan strategy was to exhaust the Athenians by endlessly ravaging the Athenian countryside; the invaders did so under command of king Archidamus II, after whom the first phase of the Peloponnesian War is called Archidamian War.
The Athenians, on the other hand, retreated behind their Long walls, received food supplies from overseas, accepted the loss of their land, and used their fleet to strike at the coastal towns of the Peloponnese. This strategy, which was designed by Pericles, soon proved to be too expensive. Pericles' death, however, saved Athens from bankruptcy. New leaders like Cleon came to power, reorganized the city's finances, and embarked upon a more ambitious strategy to bring down the Spartans.
One of the men who rose to importance was a military commander named Demosthenes, the son of Alcisthenes. Thucydides, the author of the History of the Peloponnesian War, mentions him for the first time as commander in 426. Demosthenes commanded a fleet that was sent to the Athenian naval base Naupactus in the west, where the Athenians obstructed any ship that was sailing to or from Corinth, Sparta's main naval ally. In the preceding years, the Athenian admiral Phormio had already achieved spectacular successes, and had gotten involved in a conflict between the inland tribes.
When Demosthenes appeared on the scene, there were two places where he could intervene:
- the isle of Leucas, the only island in the region that supported the Spartan case; the Ambracians wanted Demosthenes to do this and promised help.
- Aetolia, a relatively backward area that threatened Naupactus.
Demosthenes preferred the second option, because Naupactus was absolutely vital to Athenian interests, and its inhabitants had to know that they could always rely upon their powerful ally.
And so, Demosthenes ignored Leucas and invaded Aetolia, only to discover that his Ambracian allies refused to follow him. To them, Leucas was the only thing that really mattered. Other allies, the Locrians, did not turn up either when Demosthenes attacked Aetolia, from where he wanted to proceed to Boeotia, which was, at the same moment, under attack from the Athenian general Nicias. Although Demosthenes was at first successful, he soon found out that his heavy-armed hoplites were too slow for a fight fight against the light-armed Aetolians; had the Locrian javelin throwers been there, things would have been different, but in the end, Demosthenes had to admit that he had made a big mistake.
By the end of the season, he had lost 120 of his 300 marines, lost an opportunity to capture Leucas, and lost the possibility to return to Athens, where he would be accused.
During the winter of 426/425, the Aetolians invited the Spartans to join them. With some justification, they believed Naupactus was now vulnerable, and indeed, it was hard to see where it could find allies now that the Ambracians had refused help. But the Aetolians and Spartans had underestimated Demosthenes. While they were laying waste the Naupactian countryside, Demosthenes managed to reach the Ambracians and -surprisingly- convinced them to join him. With an Ambracian army, he returned to Naupactus. The Spartans knew that they could not storm the city and retreated.
They decided to attack a town called Amphilochian Argos, a town of the Acarnanians that was also claimed by the Ambracians, who became natural allies for the Spartans. Demosthenes, now a private citizen, immediately followed the Spartans to the north with a group of volunteers. Near Argos, the two armies met, but for five days, they did nothing. Finally, the Spartan commander Eurylochus decided to move. The troops joined battle, and the Spartans discovered that Demosthenes had used the previous days to create a perfect ambush. He left his left flank deliberately weak, allowed the Spartans to encircle him, and then ordered a hidden reserve to attack the Spartans, who panicked. Demosthenes' victory was complete.
The Spartan army had lost two of its three commanders. The remaining general, Mendaeus, and the surviving Spartans were besieged, and decided to surrender. Demosthenes offered them a safe passage, but continue the war against the allies of the Spartans: the Ambracians. This was a brilliant psychological trick, because in the long run, no one in this region trusted the Spartans any more.
Not much later, an Ambracian army arrived - too late to help the Spartans, but they did not know. Demosthenes was able to surprise the Ambracians and wiped out the entire army. Thucydides comments that this was the greatest disaster that befell any Greek city during the war. The western theater of operations was now completely dominated by Athens, and Demosthenes returned home, where he was hailed as a hero.
Even better was to come. On his way home, Demosthenes spotted a port called Pylos in the southwest of the Peloponnese. He noticed that it could easily be fortified, and that the Athenians could use it as a base for further raids in the area. Moreover, this part of the Peloponnese, Messenia, was hostile towards the Spartans, who had subdued the inhabitants, had made helots of them, and terrorized them. The Athenian garrison at Pylos offered them an opportunity to escape, which would greatly damage the Spartan economy. It was an imaginative plan, and the statesman Cleon was able to see to its financing.
When Demosthenes had landed at Pylos in the spring of 425, the Spartans immediately sent an army, which included their future commander Brasidas. They used the isle of Sphacteria as their base, and were isolated on this island when the Athenian navy defeated the Spartan ships. No less than 292 Spartan soldiers, including 120 elite Spartiates, were now cut off.
This was a very, very important victory. Immediately, the Spartans offered a truce, because they were unwilling to sacrifice their men. They proposed a peace treaty and good will for the future, but Cleon immediately brushed it aside. There was no guarantee that the Spartans would not change their mind later. If they wanted peace, they needed to offer something better, including some sort of guarantee for future peace. So, the war was resumed, but it was a different war: it had been shown that Sparta would stop fighting when its own people were imperiled, and would betray its allies by concluding a peace treaty.
Still, many Athenians thought that Cleon had made a mistake, and he was more or less forced to create an even bigger victory. And so he did. He went to Pylos, spoke to Demosthenes, and attacked the Spartans on the island, who in the end surrendered. This was another blow for the Spartans and sincerely handicapped them, because they could no longer attack Athens - the hostages would be executed..
In 424, the Athenians embarked upon a more ambitious strategy. In the spring, they tried to capture Megara by surprise; however, the Spartan commander Brasidas happened to be in the neighborhood and was able to foil the attempt.
Not beaten yet, the Athenians tried a second plan. One of Sparta's allies was Thebes, the capital of a federation of towns that was called Boeotia. If Athens could force Thebes out of the war, it had the security it needed to sign a peace treaty with Sparta. The Athenian plan was brilliant: from two sides, Boeotia would be invaded - from the northeast, at Delium, and from the south, where Demosthenes was to be in charge of the attack. Unfortunately, the plan was betrayed, and when Demosthenes arrived at Siphae, where he was supposed to find a friendly garrison, he was unable to reach his goal. The other army was defeated at Delium.
It was not a disaster, but more or less at the same time, the Athenians lost Amphipolis to the Spartan general Brasidas. The combination of this defeat and the unsuccessful attacks forced the Athenians to reconsider their possibilities. Demosthenes was discredited, and when his ally Cleon was killed in action during an attempt to recapture Amphipolis, Athens was willing to agree to a peace treaty. In March 421, the Peace of Nicias was signed. Demosthenes, who had been out of favor for some time, was still important enough to be one of those who swore the oaths. The Archidamian War was over.
Although the Peace of Nicias had been forced upon two exhausted enemies, it was an Athenian victory. Sparta had gone to war to dissolve the Athenian alliance, the Delian League, and had failed. Moreover, the Athenian finances were better than those of Sparta. Athens was soon full of energy again and, led by Alcibiades, allied itself to towns on the Peloponnese (discussed here). Demosthenes was not one of the main war leaders, but we know that he still played a role in the Athenian politics. In 418/417, when a major battle was fought at Mantinea (text) and Sparta restored its prestige, he conducted a minor operation in Epidaurus.
In 415, the Athenians sent an armada to Sicily, commanded by Nicias (who fell ill), Alcibiades (who was recalled), and Lamachus (who was killed in action). The Sicilian Expedition was a great strategic mistake, but the Athenians did not realize it until it was too late. The war culminated in the siege of Syracuse, which was lost by the Athenians because they were unable to surround the city with a palisade. The Syracusans, commanded by Gylippus of Sparta and Hermocrates of Syracuse, were able to build counterwalls and keep open their lines of communication.
Still, the Athenians decided to continue the siege, and sent reinforcements, commanded by Demosthenes. This was a bold move, because early in 413, the Spartan king Agis II occupied Decelea near Athens, which marked the beginning of the Decelean or Ionian War. Perhaps the Athenians believed that success at Syracuse might deter other enemies.
Demosthenes arrived in the summer of 413. The Syracusans, who had already come to believe that they would win the war, were shocked, but Demosthenes' attempt to take their counterwall by surprise was unsuccessful.
Demosthenes now realized that the war at Sicily could no longer be won, and he suggested to retreat. It was a disgrace, but there was still a chance to minimize the losses, and at least return the soldiers to Athens, where they were needed. Nicias, however, was against it, and the two commanders decided to wait a bit longer, to see if the Syracusan resistance might collapse - after all, there were reports that besieged had become weary of the war and were willing to come to terms with the reinforced Athenian army.
However, the Syracusans continued to fight, and Nicias accepted Demosthenes' proposal. Unfortunately, during the night of 27 August 413, when the Athenians were supposed to sail away, there was a lunar eclipse, which Nicias thought was a very bad omen. He ordered to stay another month.
It became almost immediately apparent that this was a serious mistake. The Syracusans now blocked the entrance of the harbor and the Athenians could no longer leave. Finally, Nicias decided to abandon his position. In fact, almost everything was now lost, because the Athenians had no ships to return home. Still, they tried to reach the safety of Catana in the north, but they were attacked by the Syracusan cavalry and were unable to make much progress.
On the sixth day of their march, they gave up, and decided to move to the south - something that the Syracusans had not expected them to do. But it did not improve the situation for the Athenians. Demosthenes' troops fell behind and surrendered on the condition that the soldiers would not be killed. Even slavery was now acceptable. On the seventh day, Nicias was able to defeat his pursuers one more time, but in the end, his men were unable to continue, and surrendered as well (text).
The Athenian POWs were forced to work in a stone quarry, where they died from malnutrition and exposure. Demosthenes and Nicias were put to death.