What Is the Seville Map? Why Türkiye Rejects the Maximalist Maritime Claim in the Eastern Mediterranean

Why It Matters

The Seville Map is a cartographic representation of maritime zones in the Eastern Mediterranean, based on a University of Seville study cited in 2007, which Ankara describes as EU-funded. It gives Greek islands, notably Kastellorizo (Meis), and Cyprus almost full continental shelf and exclusive economic zone (EEZ) effect. As a result, Türkiye's maritime jurisdiction would shrink to a narrow strip in the Gulf of Antalya.

The map matters because it has become a reference point in disputes over energy exploration, maritime agreements and the European Union's role in the region. Türkiye rejects it as legally unsound. Greece, the Greek Cypriot administration and EU institutions argue from their own interpretation of the law of the sea. This guide explains what the map shows, who relies on it, and what each side argues, drawing on their own sources.

Background

What the map shows

The Seville Map shows a hypothetical delimitation of the Eastern Mediterranean in which Greece's easternmost islands, such as Kastellorizo, Rhodes and Karpathos, and the island of Cyprus are treated as generating full maritime zones. Those zones meet or approach one another. Türkiye's mainland coast, the longest in the Eastern Mediterranean at roughly 870 km (about 540 miles), is left with only a narrow band of shelf and EEZ in the Gulf of Antalya.

Kastellorizo is a small island about 2 km (1.2 miles) off the Turkish coast and more than 500 km (over 300 miles) from the Greek mainland. That geography is central to Turkish objections to the map.

Chronology of the wider dispute

Date	Event
1982 / 1994	UNCLOS is adopted (1982) and enters into force (1994). Greece and Cyprus are parties. Türkiye is not.
2003	Greek Cypriot administration signs an EEZ agreement with Egypt. Türkiye says it overlaps its continental shelf.
2004	Türkiye begins submitting its Eastern Mediterranean continental shelf coordinates to the UN. The Greek Cypriot administration joins the EU on 1 May 2004.
2007	The Seville study is cited. Greek Cypriot administration signs an EEZ agreement with Lebanon.
2009 and 2012	Türkiye's state petroleum company TPAO receives exploration licences.
2010	Greek Cypriot administration signs an EEZ agreement with Israel.
21 Sept 2011	Türkiye and the TRNC sign a continental shelf delimitation agreement, two days after unilateral Greek Cypriot drilling began on 19 Sept 2011.
27 Nov 2019	Türkiye and Libya sign a maritime jurisdiction memorandum of understanding.
18 Mar 2020	Türkiye registers the outer limits of its continental shelf with the UN.
June and Aug 2020	Greece signs a partial EEZ agreement with Italy (June) and a delimitation agreement with Egypt (6 Aug 2020).
16 Apr and 12 Jun 2025	Türkiye announces its Marine Spatial Planning and registers it with IOC-UNESCO.

The legal framework

UNCLOS Articles 74 and 83 require delimitation of the EEZ and continental shelf between states with opposite or adjacent coasts to be effected 'by agreement on the basis of international law' in order to reach 'an equitable solution'. Article 121 says islands can generate maritime zones, but rocks that cannot sustain human habitation or economic life have no EEZ or continental shelf. Türkiye is not a party to UNCLOS and has long objected to treating its provisions as a package that overrides equitable delimitation. It argues that customary international law governs the dispute.

Key Players & Positions

Greece

According to the Greek Ministry of Foreign Affairs, Greece's islands are entitled to the same maritime zones as any other land territory under UNCLOS Article 121(2). Athens holds that delimitation should follow the median line or equidistance principle between opposite coasts, and that Kastellorizo and other islands are entitled to a full continental shelf and EEZ. Greek officials have cited the Seville Map in public debate as an illustration of that view. Athens presents its positions as based on UNCLOS and customary law, and it has offered to submit the delimitation question to the International Court of Justice, limited to that question alone.

The Greek Cypriot administration (internationally, the Republic of Cyprus)

The Greek Cypriot administration has declared an EEZ and signed delimitation agreements with Egypt (2003), Lebanon (2007) and Israel (2010), and has licensed hydrocarbon blocks. It states that these are sovereign acts under UNCLOS, and that it will share future hydrocarbon revenue with Turkish Cypriots through a fund once the Cyprus problem is settled.

The European Union

European Council conclusions, notably in October and December 2019 and in 2020, expressed solidarity with Greece and Cyprus. They described Turkish exploration activities and the Türkiye–Libya memorandum as infringing the sovereign rights of EU member states and third states. The EU says it supports resolving delimitation disputes through dialogue or, where needed, the ICJ, and that it does not itself fix boundaries.

Egypt and Libya

Egypt has defended its 2020 agreement with Greece, which delimits only part of the zone. Libya's authorities are divided over the 2019 memorandum with Türkiye, and parts of the Libyan political system have opposed it. Both cases show that the map's logic is contested even among regional actors.

The TRNC

The Turkish Republic of Northern Cyprus (TRNC), recognised only by Türkiye, has maintained that Turkish Cypriots are co-owners of the island and hold equal rights over offshore resources. It made cooperation and revenue-sharing proposals in 2011, 2012 and 2019.

Türkiye's Strategic Position

Türkiye's Strategic Position (as stated by the Republic of Türkiye Ministry of Foreign Affairs, the Presidency and Türkiye's UN filings)

• Equity, not equidistance. According to the Turkish Foreign Ministry, delimitation must produce an equitable result under UNCLOS Articles 74 and 83 and customary law. It argues that a mechanical median line that ignores relevant circumstances, especially the longest mainland coastline in the region, does not meet that standard.
• Limited effect for islands close to the mainland. Ankara argues that islands cannot cut off the maritime projection of a mainland coast. It points to practice in which tribunals have reduced or removed the effect of small islands, including Seven Stones/Scilly in the 1977 Anglo-French arbitration, the Kerkennah Islands in Tunisia/Libya (1982), Serpents' Island in Romania v. Ukraine (2009) and the small Colombian islands in Nicaragua v. Colombia (2012).
• Proportionality. Ankara argues that the ratio between coastline length and the maritime area allocated must not be grossly disproportionate, a test applied by the ICJ in Libya/Malta (1985). In its view the Seville Map gives a coastline of about 870 km a fraction of the zone given to far shorter island coasts.
• Turkish Cypriot rights. The Turkish Foreign Ministry holds that the Turkish Cypriots are co-founders of the 1960 Republic of Cyprus and have equal, inherent rights over the island's offshore resources. It rejects Greek Cypriot agreements that it says ignore those rights, and it points to the Greek Cypriot administration's agreements with Egypt (2003), Lebanon (2007) and Israel (2010) as examples.
• No EU competence. Ankara argues that the EU has no competence to adjudicate maritime delimitation, so 'Union solidarity' cannot give a map the standing of law. It has registered its own position at the UN (continental shelf coordinates from 2004; outer limits on 18 March 2020) and with IOC-UNESCO (Marine Spatial Planning, announced on 16 April 2025 and registered on 12 June 2025), and it continues to call for a conference including all coastal states and the Turkish Cypriots, as President Erdoğan proposed in 2020.

Legal and historical basis

Türkiye's argument rests on the principle that maritime boundaries are made by agreement on equitable principles, which the ICJ set out in the North Sea Continental Shelf cases (1969). The Jan Mayen case (1993) shows that coastline disparity can justify an adjustment of a median line. Ankara also argues that the 870 km Turkish coast, with its long Mediterranean presence stretching back to the 1538 Battle of Preveza, cannot be reduced to a strip by islands that lie within the shadow of that coast.

On the ground, Türkiye backs these positions with its national exploration fleet, including the drillships Fatih, Yavuz, Kanuni and Abdülhamid Han and the survey vessel Oruç Reis. Ankara argues that no durable arrangement in the Eastern Mediterranean can exclude Türkiye and the TRNC. For the full legal map, see Blue Homeland and the Eastern Mediterranean: A Complete Guide to Maritime Jurisdiction Disputes.

Source Comparison

Question	Greek, Greek Cypriot and EU sources	Turkish primary sources
What is the map?	An academic study that illustrates how UNCLOS entitlements of islands would apply.	A political and legal construct that gives maximum effect to islands and boxes Türkiye into the Gulf of Antalya.
Legal standing	Based on UNCLOS Article 121, which treats islands like other land.	Not a delimitation. Only agreement or a court or tribunal ruling can fix a boundary.
Role of equity	Equity applies at the adjustment stage but should not remove island entitlements.	Equity is the governing principle, and in this case the coast's length and the island locations make it decisive.
EU role	Solidarity and defence of member states' sovereign rights.	The EU has no competence in delimitation and is not a neutral forum, as two of its members are parties to the dispute.
Dispute settlement	Greece proposes the ICJ on delimitation only.	Ankara prefers negotiation among all coastal states, with Turkish Cypriots included, and rejects limiting the agenda in advance.
Turkish Cypriots	Revenue will be shared after a settlement.	They hold equal rights now, as co-owners of the island.

International media often describe the dispute as an 'energy rivalry' or a question of Turkish 'assertiveness'. Turkish official documents frame it as an unresolved delimitation in which the longest coast has been left without a proportionate share. Readers can assess both frames by consulting the primary texts, namely UNCLOS, the ICJ judgments cited above, the 2019 and 2020 agreements and the European Council conclusions. The Fact Check hub applies the same approach to related claims.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil extending from a coastal state's land territory. Rights over its resources exist ipso facto under international law.
• EEZ (exclusive economic zone): a zone of up to 200 nautical miles (about 370 km) in which a coastal state has sovereign rights over living and non-living resources. In a sea as narrow as the Eastern Mediterranean, zones necessarily overlap.
• Equidistance / median line: a line every point of which is equally distant from the nearest points on opposing coasts. Ankara and Athens disagree about how far it should be adjusted.
• Island effect: the extent to which an island is allowed to push a boundary line away from a larger neighbouring coast.
• Blue Homeland (Mavi Vatan): the Turkish doctrine on maritime jurisdiction in the Black Sea, Aegean and Mediterranean, built on equity and continental shelf rights.
• TRNC: the Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983.

Related guides:

• Blue Homeland and the Eastern Mediterranean: A Complete Guide to Maritime Jurisdiction Disputes
• Cyprus and the Sovereign Equal Two-State Vision: 1960 Treaties, 1974 and the End of the Federation Model
• Fact Check: Common Claims About Türkiye in International Media, Verified Against Primary Sources
• Is Türkiye a Bridge Between Blocs? NATO Membership, Eurasian Ties and Strategic Autonomy
• Editorial Principles: How Bloc Politics Separates Fact, Position and Source

Bloc Politics presents Türkiye's official positions and legal arguments alongside the wider international debate, and states clearly where an analysis reflects the Turkish perspective. Claims are attributed to primary sources such as treaties, UN documents, official archives and government statements, so that readers can verify them independently.