Data
Date	431 – 404 a. C.
Place	Aegean Sea area.
Belligerents	Athens vs. Sparta.
Outcome	Victory of Sparta.

The Peloponnesian War was a warlike conflict that occurred in Ancient Greece between the cities of Athens and Sparta, by the commercial-military power of Greece and the Aegean Sea . This occurred between the years 431 and 404 BC. C, that is, for 27 years.

In this war two great city-states of Ancient Greece faced each other:

• The League of Delos : headed by the city of Athens.
• The Peloponnesian League : headed by the city of Sparta.

Greece, the Greek islands, and the territories around the Aegean Sea were made up of independent city-states that frequently engaged in armed struggles for control of new territories and trade, or rivalries between their leaders. Causes and consequences of Peloponnesian war

Among these wars, the Peloponnesian one stands out, which was caused when Athens , then the capital of Greece, began to have more economic and military relevance due to maritime dominance. His main rival, Sparta, reacted to this, and managed to subdue the people of Athens and leave them completely devastated.

Although it is Sparta who emerged victorious from the conflict, it is believed that this war did not have a real victor, since it ended the prosperity and power that Greece had at that time .

Enhance your reading: Peace of Westphalia with consequences in detail

Causes and consequences of the Peloponnesian war

Causes

Previously, during the year 445 a. C., a peace agreement had been signed between several cities of Greece. In this treaty, Athens had been in charge of the maritime domains and the accesses to the Mediterranean Sea .

Later, when trade flourished through this route with other Mediterranean peoples and cultures, the Athenians began to have greater power than the rest of the cities of Greece, which caused friction and disagreements in the area.

So much so that Sparta, the great rival of Athens, started the war with the justification of avoiding the excessive growth of military and economic power that Athens exercised over the rest of the Greek cities .

In this way, the war was simply a fight for Greek hegemony . The war of Corinth and Corcyra was also relevant , which was a trigger for war in the area and ended the old peace treaty.

Consequences

The main consequences of the Peloponnesian War were as follows:

• The League of Delos was dissolved, led by Athens, who lost the military and economic power it had over the region.
• A debt of the Greeks with Persia was generated , reason why  the level of poverty was raised and the resources were depleted.
• Due to the weakening of the Athenian fleet, which prevented piracy practices , these intensified. 
• There was a great religious, moral, ideological and political crisis in all of Ancient Greece.
• On a demographic level, it is believed that approximately 70,000 Athenians died, equivalent to almost half of its population. Causes and consequences of Peloponnesian war
• For its part, Sparta became the main city of Greece .

Phases of the Peloponnesian War

According to various historians, the Peloponnesian War was divided into 3 stages.

Archdynamic War

This first stage of the Peloponnesian war includes from the year 431 a. C. until 421 a. C., the year that a peace treaty, called Paz de Nicias, was signed between the cities involved.

During the 10 years of this stage, Sparta launched repeated attacks on Athens, who took advantage of its maritime supremacy to defend itself. Four armed conflicts are distinguished during this phase: l to war Periclean Athens offensive war, the Athenian occupation of Pylos and Esfacteria, and finally the Peace of Nicias .

Sicilian War

This stage includes from the year 415 a. C. until 413 a. C., and this is when, after a period without armed conflict, the peace treaty between both sides was broken .

Athenian troops were sent to dominate cities allied militarily with Sparta, and there they fought a bloody battle that ended with the defeat of the Athenian army and the enslavement of its men as prisoners of war .

Enhance your reading: Peace of Augsburg with consequences in detail

Decelia’s War

The Decelia War, also known as the Ionian War, is considered the final stage of the Peloponnesian War. This happened between the years 413 a. C and 404 a. C .

During this stage  Sparta received the support of Persia and the satraps of Asia Minor , who devised military strategies and completely defeated the Athenian army .

Importance of the Peloponnesian War

This war marked the end of a long golden period of Athenian culture and rule within the history of Ancient Greece. In addition, from it different cultures began to flourish around Greece, which progressively took hold and surpassed it. Causes and consequences of Peloponnesian war

The Peloponnesian War led to  a period of decline and poverty in Greece, particularly in Athens, which came under the rule of Sparta . He began a period called “the Thirty Tyrants” that consisted of oligarchy magistrates who ruled cruelly and bloody over Athens.