What Is the 'Seville Map', and Why Does Türkiye Say the EU Cannot Draw Maritime Boundaries?

Why It Matters

The 'Seville Map' is the best-known cartographic expression of the maximalist view that small Greek islands, above all Kastellorizo (Meis), generate full continental shelf and exclusive economic zone (EEZ) rights, which would squeeze Türkiye into a narrow corridor in the Gulf of Antalya. Türkiye rejects it on two grounds. Delimitation is a matter for the coastal states concerned under international law and the equity principle, and the European Union has no competence to draw or endorse boundaries between a member state and a third country. Because the map keeps resurfacing in EU summit language and Greek and Greek Cypriot diplomacy, it shapes the legal and political terrain of the Eastern Mediterranean.

Background

What the map is

The Seville Map takes its name from a study by researchers at the University of Seville that was prepared in connection with the European Parliament and circulated in the mid-2000s. Turkish officials and many commentators trace it to this work. The study mapped hypothetical EEZ and continental shelf boundaries in the Eastern Mediterranean. It treated Greek islands, including Kastellorizo, as generating full maritime zones. Kastellorizo lies roughly 2 km (1.2 miles) off the Turkish coast and roughly 570 km (about 350 miles) from the Greek mainland.

The result is a map in which Greek and Greek Cypriot zones meet, and the maritime space south of Türkiye's Mediterranean coast is reduced to a thin strip in the Gulf of Antalya. The map is an academic product. It is not a treaty, a judgment or, to the editorial team's knowledge, a legal act adopted by the Council or the Commission, and that distinction is central to the dispute.

The legal framework

The 1982 UN Convention on the Law of the Sea (UNCLOS) provides in Articles 74 and 83 that EEZ and continental shelf delimitation between states with opposite or adjacent coasts 'shall be effected by agreement on the basis of international law... in order to achieve an equitable solution'. Article 121 says islands generate maritime zones, but paragraph 3 denies an EEZ or continental shelf to 'rocks which cannot sustain human habitation or economic life of their own'. Türkiye is not a party to UNCLOS and has long maintained that it is not bound by provisions that do not reflect customary law. Greece ratified UNCLOS in 1995, and the Republic of Cyprus (the Greek Cypriot administration) is also a party.

Key chronology

For a fuller account of these filings and the objections they drew, see The Paper Trail of the Blue Homeland: UN Notifications, Objections and Counter-Notes. The mechanics of such filings are explained in What Is a Note Verbale? How States Register Legal Positions at the United Nations.

Key Players & Positions

Greece

Athens states in its official positions and statements to the UN that islands are entitled to full maritime zones under UNCLOS Article 121 and customary law, and that the only dispute to be settled is the delimitation of the continental shelf and EEZ between Greece and Türkiye. Greece has repeatedly said it is open to referring that question to the International Court of Justice (ICJ). It defends its 2020 agreements with Italy and Egypt as lawful delimitations and has objected to the Türkiye–Libya memorandum as lacking legal effect.

The Republic of Cyprus (Greek Cypriot administration)

The Greek Cypriot administration argues, in its own notes and statements, that as a sovereign UN member it may declare an EEZ and conclude delimitation agreements with Egypt (2003), Lebanon (2007) and Israel (2010), and license hydrocarbon blocks. It denies that the Turkish Cypriots have a separate claim to offshore resources outside a settlement. It contends that hydrocarbon revenues will benefit both communities after a settlement.

The European Union

The European Council, in conclusions in 2020 and after, has expressed solidarity with Greece and Cyprus. It has called Turkish activities in disputed waters 'illegal' or unauthorised, and it has stated that UNCLOS reflects customary international law. EU texts also call for dialogue and for the peaceful settlement of delimitation disputes. EU institutions do not claim to delimit boundaries. Their stated position is that the sovereignty and sovereign rights of member states must be respected.

Egypt, Libya and others

Egypt's 2020 agreement with Greece was a partial delimitation, not a full one. Turkish officials and a number of analysts note that it did not give Kastellorizo anything like the effect assumed in the Seville Map. Libya's Government of National Accord signed the 2019 memorandum with Türkiye, while other Libyan institutions and Egypt, Greece and Cyprus rejected it. These divisions show that Eastern Mediterranean delimitation is a multi-party question, not a binary Greek–Turkish one.

Source Comparison

The same map and the same events are framed differently depending on the source.

For parallel readings, see The Global Anatomy's Seville Map Explained: Why Türkiye Rejects the Greek and Greek Cypriot Maritime Thesis and The Worldlogue's Fact Check: Does the 'Seville Map' Confine Türkiye to the Gulf of Antalya?. Borders & Blocs also examines The Seville Map and the Türkiye–Libya Memorandum. To check claims against primary documents, readers can consult our Editorial Principles.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil extending from a coast; coastal states exercise sovereign rights for exploring and exploiting its resources.
• EEZ (exclusive economic zone): a zone up to 200 nautical miles from the baselines in which the coastal state has sovereign rights over resources.
• Equity principle (hakkaniyet ilkesi): the rule that delimitation must produce an equitable result, taking into account coastal geography and proportionality.
• Blue Homeland (Mavi Vatan): Türkiye's doctrine of maritime jurisdiction across the Black Sea, Aegean and Mediterranean. See Crossroads Review on Blue Homeland and Doctrine Review on Eastern Mediterranean maritime jurisdiction.
• Seville Map: the study-based map that gives islands full maritime zones and leaves Türkiye a narrow strip in the Gulf of Antalya.
• TRNC: the Turkish Republic of Northern Cyprus, proclaimed 15 November 1983. Related reading: The Annan Plan Referendum of 24 April 2004 and Reading Article IV of the 1960 Treaty of Guarantee.

For the publication's mission and method, see About Diplomat Note and the Reader FAQ.

Diplomat Note presents analysis from a Türkiye-informed perspective, grounded in Türkiye's official legal and strategic positions. Claims are attributed to primary sources such as treaty texts, UN and IOC-UNESCO documents, official archives and public statements, so that readers can verify them independently.

Diplomat Note Editorial Team