--- title: "Megarian Decree | Ancient Mediterranean" description: "The Megarian Decree was Athens' trade ban on Megara in 432 BCE, a sanction that worsened Greek tensions and helped spark the Peloponnesian War." canonical: "https://fiveable.me/ancient-mediterranean/key-terms/megarian-decree" type: "key-term" subject: "Ancient Mediterranean" unit: "Unit 9" --- # Megarian Decree | Ancient Mediterranean ## Definition The Megarian Decree was an Athenian trade ban on Megara in 432 BCE that blocked Megarian merchants from Athenian markets and helped push Athens and Sparta toward war. ## What It Is The Megarian Decree was an economic punishment passed by Athens against Megara in 432 BCE. In practical terms, it barred Megarian merchants from trading in markets tied to the Athenian Empire, cutting off access to a major commercial network. In Ancient Mediterranean history, this is not just a random trade rule. It shows how Athens used its power as a leading naval state to pressure smaller Greek cities. Because Athens controlled sea lanes and imperial markets, a decree like this could hit a city-state hard without a direct battle. The immediate background matters. Athens and Megara were already in a tense relationship, and the decree was connected to complaints that Megara had been sheltering runaway slaves and violating Athenian interests. Whether you see the decree as a response to provocation or as aggressive economic coercion, it was a way of turning political anger into material pressure. That pressure mattered because Greek city-states depended on access to trade, grain, and allies. For Megara, being shut out of Athenian markets was not a minor insult. It damaged revenue, limited commerce, and made Sparta look like the only major power able to stand up to Athens. The decree is also useful because it shows how the Peloponnesian War did not begin with one battlefield incident. It came out of a growing chain of grievances, alliance politics, and fear of Athenian expansion. Sparta and its allies saw the decree as one more sign that Athens was using its strength too aggressively, and that perception helped harden the coalition against Athens. ## Why It Matters The Megarian Decree matters because it is one of the clearest examples of how economic pressure can become a cause of war in Greek history. In the story of the Peloponnesian War, it sits right at the point where tension turns into open conflict. It also helps you read Athens more carefully. Athens was not only a democracy with philosophers and temples, it was an empire that used markets, naval power, and alliances to control behavior. The decree shows that power in the Greek world was not only about armies on land. It could also mean who got to trade, who got excluded, and who could survive under a blockade-like restriction. For the broader unit on the Peloponnesian War, this term gives you a concrete trigger to connect to bigger causes like rivalry between Athens and Sparta, fear of Athenian dominance, and the collapse of peace. If you can explain why Megara reacted so strongly, you can explain why neutral-looking economic policy became a political crisis. ## Connections ### Peloponnesian War The Megarian Decree is usually discussed as one of the immediate causes of the Peloponnesian War. It did not start the conflict by itself, but it made tensions much worse by turning a dispute over trade and punishment into a wider crisis between Athens and Sparta. ### Delian League Athens' ability to enforce the decree came from the larger power structure it built through the Delian League. That network gave Athens money, ships, and influence, which meant a trade ban could have real bite instead of being just a symbolic threat. ### Pericles Pericles is often linked to the politics that led Athens into confrontation with Sparta. When you study the decree, you are also studying the kind of Athenian leadership that was willing to use imperial pressure to defend Athenian interests. ### [Peace of Nicias](/ancient-mediterranean/key-terms/peace-of-nicias) The Megarian Decree belongs to the build-up to war, while the Peace of Nicias comes later as one attempt to stop the fighting. Comparing them shows the shift from escalating sanctions and hostility to a fragile diplomatic pause. ## On the AP Exam A quiz question or short-answer prompt might ask you to identify the Megarian Decree as a cause of the Peloponnesian War and explain why it mattered beyond Megara itself. You would want to connect the trade ban to Athenian power, Spartan resentment, and the broader breakdown of peace between the Greek city-states. In an essay or discussion response, use it as evidence that Greek warfare was shaped by economics and alliance politics, not just battlefield clashes. If you see a question about why Sparta and its allies felt threatened by Athens, the decree is a strong example because it shows Athens using imperial control to punish an enemy through commerce. ## Megarian Decree vs Peace of Nicias These are often mixed up because both appear in the Peloponnesian War timeline, but they are opposites in purpose. The Megarian Decree helped escalate conflict before the war, while the Peace of Nicias was a later truce meant to reduce it. ## Key Takeaways - The Megarian Decree was an Athenian trade ban on Megara in 432 BCE. - It worked by blocking Megarian merchants from Athenian markets and hurting Megara's economy. - The decree is one of the immediate causes of the Peloponnesian War because it intensified conflict between Athens and Sparta. - It shows that economic sanctions could be as politically explosive as military action in the Greek world. - When you study it, focus on how trade, empire, and alliance politics connected to the outbreak of war. ## FAQs ### What is the Megarian Decree in Ancient Mediterranean? The Megarian Decree was an Athenian economic sanction against Megara in 432 BCE. It banned Megarian merchants from trading in Athenian-controlled markets, which hurt Megara's economy and increased tension with Sparta. ### Why did Athens pass the Megarian Decree? Athens passed the decree in response to grievances against Megara, including accusations that Megara had sheltered runaway slaves and acted against Athenian interests. It was both a punishment and a show of Athenian power. ### How did the Megarian Decree help cause the Peloponnesian War? The decree gave Sparta and its allies another reason to see Athens as aggressive and overbearing. By damaging Megara through trade restrictions, Athens made the dispute feel like a wider threat to the balance of power in Greece. ### Is the Megarian Decree a military action or an economic one? It was an economic action, not a battle. That is why it is such a useful example in Ancient Mediterranean history, because it shows how trade restrictions could help trigger major political and military conflict. ## Related Study Guides - [9.1 Causes and phases of the Peloponnesian War](/ancient-mediterranean/unit-9/phases-peloponnesian-war/study-guide/xf3NmG0NJpuejSBl) ## About This Document Canonical Fiveable pages are available as Markdown at the same path plus `.md`. - [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns - [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing - [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`) - [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`) ## Structured Data ```json {"@context":"https://schema.org","@graph":[{"@type":"LearningResource","@id":"https://fiveable.me/ancient-mediterranean/key-terms/megarian-decree#resource","name":"Megarian Decree | Ancient Mediterranean","url":"https://fiveable.me/ancient-mediterranean/key-terms/megarian-decree","learningResourceType":"Concept explainer","educationalLevel":"AP® / High School","about":{"@id":"https://fiveable.me/ancient-mediterranean/key-terms/megarian-decree#term"},"audience":{"@type":"EducationalAudience","educationalRole":"student"},"dateModified":"2026-07-03T02:21:02.382Z","isPartOf":{"@type":"Collection","name":"Ancient Mediterranean Key Terms","url":"https://fiveable.me/ancient-mediterranean/key-terms"},"author":{"@type":"Organization","@id":"https://fiveable.me/editorial#content-team","name":"Fiveable Content Team","url":"https://fiveable.me/editorial","parentOrganization":{"@id":"https://fiveable.me/#organization"},"member":[{"@type":"Person","name":"Amanda DoAmaral","sameAs":["https://www.linkedin.com/in/adoamaral"]},{"@type":"Person","name":"Becky Bahr","sameAs":["https://www.linkedin.com/in/becky-bahr-b52743132"]}]},"publisher":{"@type":"Organization","name":"Fiveable","url":"https://fiveable.me"}},{"@type":"DefinedTerm","@id":"https://fiveable.me/ancient-mediterranean/key-terms/megarian-decree#term","name":"Megarian Decree","description":"The Megarian Decree was an Athenian trade ban on Megara in 432 BCE that blocked Megarian merchants from Athenian markets and helped push Athens and Sparta toward war.","url":"https://fiveable.me/ancient-mediterranean/key-terms/megarian-decree","inDefinedTermSet":{"@type":"DefinedTermSet","name":"Ancient Mediterranean Key Terms","url":"https://fiveable.me/ancient-mediterranean/key-terms"}},{"@type":"FAQPage","mainEntity":[{"@type":"Question","name":"What is the Megarian Decree in Ancient Mediterranean?","acceptedAnswer":{"@type":"Answer","text":"The Megarian Decree was an Athenian economic sanction against Megara in 432 BCE. 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