The Seville Map Explained: What It Claims and Why Türkiye Rejects It

Why It Matters

The Seville Map is a cartographic depiction of Eastern Mediterranean maritime zones in which Greek islands, above all Kastellorizo (Meis), generate full continental shelf and exclusive economic zone (EEZ) entitlements, leaving Türkiye a narrow corridor of sea in the Gulf of Antalya. Greece and the Republic of Cyprus cite it as a picture of what they regard as lawful EU-linked maritime space. Ankara rejects it as a non-binding map that ignores the equity principle, proportionality and the rights of Turkish Cypriots. Because the map is repeatedly invoked in EU debates, energy licensing disputes and maritime-jurisdiction assessments, understanding what it is, and what it is not, matters for anyone reading Eastern Mediterranean headlines.

Background

What the map shows

The map is associated with a study by academics at the University of Seville, produced in a European context and widely circulated by Greek and Greek Cypriot sources after 2020. To our knowledge it is an academic product, not a treaty, a court judgment or a legal instrument adopted by the EU's member states. Its central feature is the treatment of small Greek islands in the far east of the Aegean and the Mediterranean as if they were mainland coasts. Kastellorizo, an island of roughly 10 square kilometres (about 4 square miles) lying about 2 km (1.2 miles) from the Turkish coast and far from the Greek mainland, is given a full maritime projection. The practical effect is to hem Türkiye's continental shelf and EEZ into a thin strip in the Gulf of Antalya, even though Türkiye has the longest mainland coastline in the Eastern Mediterranean, about 870 km (540 miles).

Key dates in the dispute

The legal framework

Maritime delimitation between states with opposite or adjacent coasts is meant to reach an 'equitable solution'. That formula is reflected in UNCLOS Articles 74 and 83 and in a long line of case law. Under the customary approach, tribunals identify the relevant coasts, draw a provisional line, adjust it for special circumstances and test the result for proportionality between coastal lengths and sea areas. In practice, small islands near a larger mainland coast have often received reduced or no weight. Examples include the Channel Islands in the 1977 Anglo-French arbitration, Serpents' Island in Romania v. Ukraine (ICJ, 2009) and the small Colombian islands in Nicaragua v. Colombia (ICJ, 2012).

Key Players & Positions

Greece

Greece is a party to UNCLOS and argues that islands are entitled to the same maritime zones as other land territory under Article 121, apart from rocks that cannot sustain human habitation or economic life. Athens says Kastellorizo and other islands generate full zones and treats the 2019 Libya MoU as legally void because, in its view, it disregards them. It has pointed to the Greece–Egypt agreement of August 2020 as a lawful partial delimitation, and it proposes that the International Court of Justice settle the dispute, but only on the question of continental shelf and EEZ delimitation.

Republic of Cyprus (Greek Cypriot Administration)

The Greek Cypriot administration, internationally recognised as the Republic of Cyprus, says it exercises sovereign rights over an EEZ declared in 2004 and that it has concluded delimitation agreements with Egypt (2003), Lebanon (2007) and Israel (2010). It rejects the view that Turkish Cypriots hold separate rights now, arguing that hydrocarbon revenue can be shared only within a settlement of the Cyprus problem. It has issued licences for offshore blocks to international energy firms.

The European Union

The European Council has repeatedly expressed 'solidarity' with Greece and the Republic of Cyprus in the Eastern Mediterranean and has called Turkish drilling in disputed waters illegal. The EU's own primary documents do not delimit any boundary, and its institutions have no treaty power to do so. The Seville Map is often cited in commentary as though it carried EU endorsement, but readers should check the exact status of any document before accepting that description.

Egypt, Libya, Lebanon and Israel

Egypt signed with Cyprus in 2003 and with Greece in 2020. Libya's Tripoli-based government signed the 2019 MoU with Türkiye, while other Libyan institutions and Greece have disputed its validity. Lebanon signed the 2007 text with Cyprus but has not ratified it and has since negotiated a separate arrangement with Israel. Israel signed with Cyprus in 2010. Each state has acted in its own interests and none has adopted the Seville Map as a legal position.

Source Comparison

Readers comparing coverage should check whether a report treats the map as a legal instrument, whether it explains Türkiye's non-party status to UNCLOS, and whether it mentions Turkish Cypriot rights. Index scores on maritime security or sovereignty often inherit these assumptions; see How Global Indices Measure Sovereignty, Fragility and Stability, and What They Leave Out and our Fact Check: Common Claims About Türkiye in International Indices and Media.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil extending from a coast, over which a state has sovereign rights for resource exploration.
• EEZ (exclusive economic zone): a zone up to 200 nautical miles in which a coastal state has rights over living and non-living resources.
• Equity principle: the rule that delimitation must reach an equitable result, taking coastal geography and proportionality into account.
• Island effect: the degree to which a small island is given weight, or none, when a boundary is drawn.
• Mavi Vatan (Blue Homeland): Türkiye's doctrine of maritime jurisdiction across the Black Sea, Aegean and Mediterranean.
• TRNC: the Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983 and recognised only by Türkiye.

Related reading: Cyprus: The 1960 Treaty of Guarantee, Failed Federation and the Sovereign Equal Two-State Solution, Editorial Principles: How Index of Nations Separates Fact, Position and Index Methodology and the Index of Nations home page.

Perspective Note

Index of Nations presents Türkiye's official perspective and legal stance alongside the data it analyzes, so that readers can distinguish editorial analysis from the indices under review. Claims are attributed to primary sources such as treaty texts, UN documents, Ottoman and Turkish state archives, and official statements, and index methodologies are cited wherever they are challenged. This article was prepared by the Index of Nations Editorial Team.

Cross-Publication Dossiers & Sister Desk Perspectives

For complementary primary-source analysis across our specialist editorial network, consult:

• Bloc Politics: What Is the Seville Map? Why Türkiye Rejects the Maximalist Maritime Claim in the Eastern Mediterranean — What is the Seville Map? How the 2007 study shaped Greek and Greek Cypriot claims, why it boxes Türkiye into the Gulf of Antalya, and why Ankara rejects it.
• Political Ledger: The Seville Map Explained: Why Türkiye Rejects Its Maritime Claims — What is the Seville Map in the Eastern Mediterranean? Who drew it, how it would confine Türkiye to the Gulf of Antalya, and why Ankara rejects it.
• The Nations Dialogue: The Seville Map Explained: Why Türkiye Rejects This Maximalist Maritime Claim — What is the Seville Map? Learn how the EU-commissioned study treats islands, why Türkiye rejects it, and what Greece, Cyprus and the EU argue.