The Decelean War marked the final phase of the Peloponnesian War, with Sparta establishing a base near Athens. This strategic move, along with Persian support for Sparta, put immense pressure on Athens, disrupting its resources and economy.

Despite occasional naval victories, Athens struggled against Sparta's land-based advantages and Persian-backed fleet. The decisive Battle of Aegospotami in 405 BCE led to Athens' surrender in 404 BCE, ending its dominance and shifting power to Sparta.

Sparta's Decelea Base: Strategic Significance

Establishment and Location

• In 413 BCE, Sparta established a permanent military base at Decelea, located just 14 miles north of Athens in the region of Attica
• The proximity of the base to Athens allowed Sparta to exert significant pressure on its rival city-state

Impact on Athenian Resources and Supplies

• The Spartan presence at Decelea allowed them to disrupt Athenian supply lines, raid the Athenian countryside, and encourage the desertion of Athenian slaves
• Sparta's control of Decelea put significant pressure on Athens by threatening its food supply and economic resources, ultimately weakening the city's ability to sustain the war effort
• The base at Decelea also prevented the Athenians from effectively utilizing the silver mines at Laurium, a crucial source of revenue for funding their naval operations
• The disruption of Athens' access to resources and supplies from its surrounding territories severely hampered its war efforts and contributed to the city's eventual defeat

Persian Intervention in the Peloponnesian War

Persian-Spartan Alliance

• The Persian Empire, under King Darius II, began to intervene in the Peloponnesian War by providing financial support to Sparta in exchange for the recognition of Persian authority over the Greek cities of Ionia
• In 412 BCE, Sparta and Persia signed the Treaty of Miletus, which formally allied the two powers against Athens and secured Persian funding for the Spartan fleet
• The Persian-Spartan alliance shifted the balance of power in the Aegean, putting additional strain on Athens' resources and forcing them to fight on multiple fronts

Impact of Persian Financial Support

• Persian financial support allowed Sparta to build and maintain a more powerful navy, challenging Athenian naval supremacy and enabling Spartan victories in key battles, such as the Battle of Notium in 406 BCE
• The influx of Persian funds helped Sparta to sustain its war effort and attract new allies, further isolating Athens diplomatically and militarily
• The alliance with Persia provided Sparta with a significant advantage in terms of resources and strategic support, ultimately contributing to Athens' defeat

Athenian Naval Strategy and Key Battles

Reliance on Naval Superiority

• Despite the challenges posed by Sparta's base at Decelea and Persian intervention, Athens continued to rely on its naval superiority as a key strategy in the war
• The Athenian navy aimed to maintain control of the Aegean Sea, protect the city's trade routes, and disrupt Spartan supply lines
• Athens' naval strategy was crucial to its survival, as the city depended on maritime trade for its food supply and economic well-being

Battle of Arginusae

• In 406 BCE, the Athenians won a significant victory at the Battle of Arginusae, defeating a Spartan fleet and temporarily reasserting their naval dominance
• The victory at Arginusae provided a much-needed morale boost for Athens and demonstrated the city's continued naval capabilities
• However, the Athenian commanders at Arginusae were later tried and executed for failing to rescue survivors and recover the bodies of the dead, highlighting the political instability and internal divisions within Athens

Limitations of Athenian Naval Strategy

• Despite occasional successes, the Athenian naval strategy ultimately proved insufficient to counter the combined pressures of Sparta's land-based advantages and Persian financial support
• The Athenian navy was stretched thin, trying to maintain control over a vast maritime empire while simultaneously defending against Spartan attacks
• The loss of key allies and the increasing financial burden of maintaining a large fleet gradually eroded Athens' ability to effectively wage war at sea

Athens' Defeat and Surrender to Sparta

Battle of Aegospotami

• The Spartan victory at the Battle of Aegospotami in 405 BCE dealt a decisive blow to the Athenian navy, destroying most of its fleet and cutting off the city's access to the Hellespont, a crucial trade route for grain imports
• The loss at Aegospotami, combined with the ongoing economic strain caused by the Spartan presence at Decelea, left Athens unable to continue the war effectively
• The destruction of the Athenian fleet at Aegospotami marked the beginning of the end for Athens, as it could no longer rely on its naval superiority to protect its interests

Surrender and Terms

• In 404 BCE, faced with the prospect of starvation and internal unrest, Athens surrendered to Sparta, ending the Peloponnesian War after nearly three decades of conflict
• The terms of Athens' surrender included the dismantling of its defensive walls, the relinquishment of its naval fleet, and the acceptance of a Spartan-backed oligarchic government known as the Thirty Tyrants
• The harsh terms imposed by Sparta aimed to strip Athens of its military and political power, ensuring that the city could no longer pose a threat to Spartan hegemony

Aftermath and Shift in Power

• The defeat of Athens marked a significant shift in the balance of power among the Greek city-states, with Sparta emerging as the dominant force in the Greek world for a time
• The end of the Peloponnesian War ushered in a period of Spartan hegemony, as the city sought to expand its influence and control over the Greek world
• However, Sparta's dominance was short-lived, as its heavy-handed tactics and internal conflicts eventually led to its own decline and the rise of new powers, such as Thebes and Macedon, in the following decades