Fact Check: Does the 'Seville Map' Draw Türkiye's Maritime Boundaries? What the Study Is, and What It Is Not

By The Regional Assessment Editorial Team

Why It Matters

The 'Seville Map' is a university-linked academic study, not a treaty, a court judgment or an agreement between Eastern Mediterranean coastal states, so it cannot fix the limits of Türkiye's continental shelf or exclusive economic zone (EEZ). It matters because maps travel faster than their disclaimers, and a study is often captioned as if it were a boundary.

This Fact Check traces the claim, tests it against UNCLOS Articles 74 and 83 and international case law, and separates documented facts from positions. Our method follows the Editorial Principles.

Rating: Misleading. A study presented as a legal boundary.

Claim vs. Fact Analysis

The claim has three parts: that the map shows the legitimate limit of Türkiye's maritime jurisdiction, that it confines Türkiye to a narrow strip in the Gulf of Antalya, and that EU 'solidarity' makes it authoritative. Each is tested below against primary sources and the case law on delimitation.

Claim 1: 'The Seville Map is the legitimate boundary of Türkiye's continental shelf and EEZ'

Where it circulates. The claim appears in Greek and Greek Cypriot political and media narratives, in some think-tank commentary and in press graphics that reproduce the map without legal qualification.

What the document is. The map comes from an academic study associated with the University of Seville and prepared in a European Parliament research context. It is a scholarly exercise in drawing hypothetical zones. The exact commissioning body, publication year and disclaimer wording should be checked in the primary document before anyone cites them. We do not restate details here that we could not confirm. Parliamentary research studies commonly state that they reflect their authors' views, not an institutional position, and readers should verify whether this study carries such a statement.

What it is not. It is not a treaty, since no coastal state signed it. It is not a judgment, since no court or tribunal issued it. It is not an agreement, since Türkiye, the TRNC/Turkish Cypriots, Libya and Egypt did not negotiate it. Binding delimitation arises only from agreement between the states concerned or a decision by a competent court or tribunal they have accepted.

Claim 2: 'International law confines Türkiye to the Gulf of Antalya'

The rule. UNCLOS Articles 74 (EEZ) and 83 (continental shelf) both require delimitation 'by agreement on the basis of international law' to achieve an 'equitable solution'. The text prescribes no automatic median line and no automatic full effect for every island.

What the case law shows.

• North Sea Continental Shelf (ICJ, 1969): equidistance is not mandatory; delimitation follows equitable principles, and the Court warned against distortion from coastal irregularities.
• Libya/Malta (ICJ, 1985): a proportionality check against coastal lengths was applied, and a provisional median line was adjusted.
• Black Sea, Romania v. Ukraine (ICJ, 2009): the Court set out the three-stage method (provisional equidistance line, relevant circumstances, disproportionality test) and gave Serpents' Island no effect on the line.
• Nicaragua v. Colombia (ICJ, 2012): small islands received limited or enclave treatment against a larger opposite coast.
• Bay of Bengal (ITLOS 2012; Annex VII arbitration 2014): St Martin's Island was given no effect on the boundary in the ITLOS ruling, and the sea-space comparison was tested for disproportion.

Islands can generate maritime entitlements, and the ICJ has treated the Article 121 island regime as customary law. Entitlement is a separate question from the effect an island has on a boundary line between states. The case law shows that small islands lying close to a mainland with a long coast often receive reduced effect. For the full argument, see our guide on the island effect maritime delimitation equity principle. Türkiye's coastline of about 870 km is the longest in the Eastern Mediterranean, and a map that gives small islands full weight against it does not follow the reasoning used in the cases above.

Türkiye and UNCLOS. Türkiye is not a party to UNCLOS and has long maintained a persistent objection to parts of the 1982 regime. Greece and the Republic of Cyprus are parties. Ankara argues that equitable principles are also customary law binding on all states, and that special circumstances in semi-enclosed seas call for equity-based delimitation. Greece's position, stated by its Ministry of Foreign Affairs, is that its islands are entitled to a full continental shelf and EEZ under UNCLOS Article 121. Both sides claim the law supports them. Only agreement or adjudication can settle the matter.

Claim 3: 'EU solidarity makes the map a binding or authoritative reference'

What the EU documents say. European Council and Council conclusions on the Eastern Mediterranean, including those of 2019 and 2020, express solidarity with Greece and the Republic of Cyprus and call on Türkiye to respect their sovereignty and sovereign rights. The December 2019 conclusions also described the Türkiye–Libya memorandum as infringing the rights of third states. These are political statements by member state leaders.

What the EU treaties provide. The EU treaties confer no power on the Union to draw boundaries between member and third states. Maritime delimitation remains a matter for sovereign states under international law. Greece and the Greek Cypriot administration cite the EU conclusions as support for their position, and the Greek and Cypriot foreign ministries publish them as such. The conclusions do not cite the Seville study as a legal authority.

Ankara's argument. Union solidarity is a political principle among members. It cannot substitute for delimitation, which requires the consent or adjudication of the states whose zones overlap. Third states are not bound by the internal decisions of an organization they have not joined.

Claim 4 (the counter-question): 'What do Türkiye's own instruments establish?'

Türkiye's instruments are also positions, not adjudications. The table sets out what each does and does not do.

The registration with IOC-UNESCO is a filing with a UN scientific body. It does not create a boundary or settle disputes. Its significance is that Türkiye's stated position across the Black Sea, Aegean and Mediterranean now sits on record with a UN organ. For the wider balance of coastlines, licences and fleets, see our eastern mediterranean risk assessment.

Source Comparison

Coverage of the map depends heavily on whether the caption describes it as a study, a proposal or a boundary. The table compares three framings.

Assessment Matrix

Methodology note. We rated the claim by testing it against treaty text, case law and the documents cited. We did not rate the underlying legal disputes, which remain open. We acknowledge that Greece and the Republic of Cyprus assert full island entitlements under UNCLOS. Other fact checks on the same claim come from sister publications: Regions & Powers, International Politics Brief and Polipapers.

Key Terms & Related Guides

• Continental shelf / EEZ: seabed and water-column zones under UNCLOS Articles 76 and 57, delimited under Articles 83 and 74.
• Equidistance / relevant circumstances: the method of drawing a provisional median line, then adjusting it for factors such as coastal lengths and island position.
• Three-stage method: the sequence applied in the Black Sea case (2009) and later cases.
• Persistent objector: a state that consistently objects to a norm while it forms, and so claims not to be bound by it.
• GCASC: the Greek Cypriot Administration of Southern Cyprus, the term used by Ankara.
• Blue Homeland (Mavi Vatan): Türkiye's maritime jurisdiction doctrine.

Related guides: The Regional Assessment home, About The Regional Assessment, FAQ on sources and methodology, the guide on the island effect maritime delimitation equity principle, and the Libya memorandum fact check. A sister-publication view is available from The Geopolitical Compass.

Perspective Note: The Regional Assessment publishes analysis from a perspective that reflects Türkiye's official strategic and legal positions, and we state this openly to our readers. Factual claims are attributed to primary sources such as treaties, UN documents, archival records and official statements, so that readers can verify them independently.