The siege of Potidaia (432-430/29) saw the
Athenians besiege a city that was part of their empire, and was one of a series
of relatively minor military clashes that helped to trigger the Great
Peloponnesian War. Potidaia was an example of a city with a foot in both camps
in the clash between Athens and the Peloponnesian League. The city was a colony
of Corinth (part of the Peloponnesian Leage), and had maintained friendly
relations with the mother city. Potidaia's annual magistrates were still
provided by Corinth. At the same time Potidaia was a member of the
Delian League, which
made it part of the Athenian empire. This would have been an awkward
relationship at the best of times, but after the outbreak of near-open
hostility between Corinth and Athens during the Corinth-Corcyra War (435-431)
the Athenians decided that the Corinthian influence would have to end. There
was also a fear that a rebellious Potidaia could trigger a wider rebellion in
Thrace, and threaten a key part of the Athenian grain supplies.
Potidaia was located on the Chalcidice peninsula, near to Macedonia. It was at
the mainland end of the Pallene isthmus (the western-most of the three narrow
isthmuses peninsulas that jut south from Chalcidice.
The Athenians made three demands - first that Potidaia send back her Corinthian
magistrates and refuse to accept any in future years, second that she send
hostages to Athens and third that the city walls facing south towards the
Pallene isthmus be dismantled.
The Potidaians responded by sending ambassadors to Athens to argue against
these demands, and to Sparta to try and seek allies. They were also aware that
King Perdiccas of Macedonia would support them if they did revolt against
Athens. Perdiccas was already involved in efforts to convince the Chalcidians
to revolt against Athens, and in response the Athenians were on the verge of
dispatching a force of 1,000 hoplites against him.
The Potidaian ambassadors to Athens failed to win any concessions, but the
ambassadors to Sparta received a promise that if Athens attacked Potidaia then
Sparta would invade Attica. When this news reached Potidaia the citizens
decided to join with the Chalcidians, and the revolt began. Soon after this the
first Athenian expedition arrived in the area, but its commanders soon realised
that they didnt have enough men to deal with all of their enemies, and
decided to focus on Perdiccas and Macedonia first. This gave the Corinthians
the time they needed to send 1,600 hoplites and 400 light troops to Potidaea.
The Athenians responded with fresh troops, sending 2,000 more hoplites under Callias, son of Calliades.
They arrived to find the first army besieging Pydna, and after a time consuming
siege were able to come to terms with Perdiccas.
The Athenian army, now reinforced by 600 Macedonian cavalry, marched east along
the coast towards Potidaia. By the time they arrived the Macedonians had
changed sides once again, and had troops with the Potidaians, Corinthians and
Chalcidians (although the original 600 cavalry may have stayed with the
Athenians). The allies split their army in two. The Corinthians and Potidaians
took up a position on the isthmus just to the north of their city, while the
Chalcidians, Macedonians and other allies took up a position at Olynthus, seven
miles to the north east.
Their plan was to wait for the Athenians to attack the troops outside Potidaia
and then attack them in the rear using the forces at Olynthus. This plan was
disrupted by the Athenians, who sent their Macedonian cavalry and some other
allies towards Olynthus, preventing the reinforcements from moving. The
Athenians then attacked the main allied army. The Corinthian wing of the allied
army, under Aristeus, was victorious, but the Athenians won everywhere else
along the line. Aristeus was only just able to fight his way back to safety
inside Potidaia by advancing in a narrow column along the waterfront.
This battle was a clear Athenian victory. The allies had lost 300 men, the
Athenians only 150 (although Callias was amongst them). The Athenians erected a
trophy to commemorate the victory, and then began to prepare for a regular
siege of Potidaia. At first they only built a wall across the head of the
isthmus (to the north of the city), in the belief that they didnt have
enough men to risk splitting their forces by building another wall to the
south. When this news reached Athens a third army was dispatched, this time of
1,600 hoplites under the command of
Phormio, son of Asopius.
This army landed at Pallene, to the south of Potidaia, and advanced along the
isthmus. When he reached the city Phormio built a line of siege fortifications
to the south, and the city was completely cut off. Aristeus, the Corinthian
commander, believed that the besieged city could no longer expect to hold out.
He advised the citizens to evacuate by sea at the first possible opportunity,
leaving a garrison of 500 men to defend the city (the same strategy that the
Athenians adopted at Plataea). After this advice was ignored, Aristeus escaped
from the city and attempted to help the defenders from outside, partly by
working with the Chalcidians and partly by called for help from the
Peloponnese. After this dramatic start the siege began to drag on.
Thucydides doesn't record any significant events at Potidaia in 431. In the
summer of 430 the largest Athenian army yet was sent against Potidaia. This
force of 4,000 hoplites, 300 cavalry, 100 triremes and fifty ships from Lesbos
and Chios was commanded by Hagnon, son of Nicias and Cleopompus, son of
Clinias, Pericles's fellow generals.
By 430 the plague had broken out in Athens, and Hagnon's army took it to
Potidaia, where it spread to the troops already engaged in the siege. Hagnon is
recorded as having used siege engines against the city, but without success,
and the plague killed 1,050 of his 4,000 men. After spending at least a month
outside Potidaia Hagnon gave up and took his army back to Athens.
Eventually the siege was ended by starvation. By the winter of 430/429 (or the
end of the second year of the war) the situation was so bad that some cases of
cannibalism had been record inside the city. The Athenians were clearly also
becoming tired with the siege, which had cost them 2,000 talents and forced
them to keep a large army in the northern Aegean. This is reflected in the
lenient surrender terms that were agreed. The Potidaeans, their wives and
children and auxiliary troops were allowed to leave the city in freedom and go
anywhere they wished. Each woman was allowed to take two garments with them,
each man a single garment, as well as a fixed sum of money for the journey.
These lenient terms caused some complaints at Athens, but they did mean that
the siege finally came to an end. The Athenians kept possession of Potidaea,
eventually resettling the city with their own colonists.