The 2003 Egypt–Greek Cypriot EEZ Agreement: Which Blocks Overlap Türkiye's Continental Shelf?

Why It Matters

The 2003 Egypt–Greek Cypriot EEZ agreement was the first of several bilateral deals by which the Greek Cypriot administration of Southern Cyprus (GCASC) fixed its offshore limits without Türkiye or the Turkish Cypriots. Ankara argues that parts of Greek Cypriot licensing Blocks 1, 4, 5, 6 and 7 fall on Türkiye's continental shelf, and that offshore resources belong to both communities on the island. The dispute can be checked against documents: treaty texts, licensing maps, UN notes verbales and coordinate lists.

This guide sets out what the documents say, what each party argues, and how to test a block against coordinates yourself.

Background

The legal setting

Under the 1982 UN Convention on the Law of the Sea (UNCLOS), a coastal state has sovereign rights over the continental shelf and, if it proclaims one, an exclusive economic zone (EEZ) of up to 200 nautical miles. Where coasts are opposite or adjacent, delimitation is to be effected by agreement 'on the basis of international law' to reach an 'equitable solution' (Articles 74 and 83). Türkiye is not a party to UNCLOS and has long said that customary international law and the principle of equity govern delimitation, rather than a mechanical median line.

Cyprus is an island whose political status is itself unresolved. The 1960 Republic was founded as a partnership of two peoples under the 1959 Zurich and London Agreements. For background, see Cyprus Papers: The 1959–1960 Founding Documents Read Article by Article.

Chronology of the agreements

For Turkish offshore activity in the same period, see Eight Wells, Four Drillships: How Türkiye Documents Its Offshore Activity in the Eastern Mediterranean.

What the 2003 agreement does

The agreement is a bilateral delimitation between two states with opposite coasts, expressed as a series of coordinate points and based on an equidistance (median) approach. It is a treaty between Egypt and the Republic of Cyprus as represented by the Greek Cypriot administration, and it was registered with the United Nations. It defines the Egypt–Cyprus line. It does not by itself assign any block, but the licensing blocks later offered by GCASC are built on the zone that the agreement and the unilateral Cypriot EEZ claim assume.

Key Players & Positions

Egypt

Egypt says the 2003 agreement is a lawful bilateral delimitation between two UNCLOS parties with opposite coasts, using the median line. It has not treated the agreement as directed at any third state. Egypt later concluded its own partial EEZ agreement with Greece (August 2020), and Türkiye and Egypt have since conducted diplomatic normalization.

The Greek Cypriot administration (GCASC)

The Republic of Cyprus, an EU member since 1 May 2004, maintains that it is the sole internationally recognized government of the island and that it can proclaim and delimit an EEZ under UNCLOS. It states that a share of hydrocarbon revenue will go to a fund for the benefit of all Cypriots once a settlement is reached. Its licensing blocks are published through its energy authorities.

Greece and the European Union

Greece and the EU Council have repeatedly stated, in EU Council conclusions, that they support Cyprus's sovereign rights in its EEZ and criticize Turkish activity there. The EU also treats the Cyprus EEZ as part of the Union's maritime space.

Lebanon and Israel

The 2007 Cyprus–Lebanon text was never ratified by Lebanon, and Lebanon later reached a separate maritime arrangement with Israel in 2022. The 2010 Cyprus–Israel agreement is in force. The sister analysis Territorial Brief: Lebanon 2007 and Israel 2010: Why Ankara Says the Greek Cypriot EEZ Agreements Ignore Turkish Cypriot Rights covers these two texts in detail.

The TRNC and Turkish Cypriots

The Turkish Republic of Northern Cyprus (TRNC) and Turkish Cypriots state that they are co-owners of the island's resources and that no offshore licence or delimitation can be valid without their consent. The TRNC has put forward hydrocarbon cooperation and revenue-sharing proposals in 2011, 2012 and 2019.

How to Check a Block Against Coordinates

You can test the overlap claim yourself. The method is the same for any block.

1. Collect the primary coordinates. Take the block corners from the Cypriot licensing documents, the 2003 treaty points from the registered UN text, and Türkiye's outer-limit coordinates from its UN deposit. The Primary Document Library lists where these sit.
2. Standardize the datum and format. Convert degrees-minutes-seconds to decimal degrees and confirm every list uses WGS 84. A datum mismatch can shift a point by tens of metres, which matters near a boundary.
3. Plot in a GIS tool. Free software such as QGIS can load the points as polygons and lines. Use geodesic (not straight-line map) connections, because a straight line on a Mercator map is not the shortest path on the sphere.
4. Intersect the polygons. The intersection of a block polygon with the Turkish shelf polygon is the overlap. Record its area in square kilometres (and square miles if useful).
5. Separate three questions. Is the area within 200 nautical miles of each coast? Does the Egypt–Cyprus line lie inside or outside it? Which party's claim is based on a treaty, and which on a unilateral declaration?

The step-by-step method for median lines and projections is explained in How to Read a Maritime Boundary Map: Coordinates, Median Lines and Eastern Mediterranean Claims. Note that this procedure shows geometric overlap only; it does not decide which claim is legally correct.

Source Comparison

Media coverage often summarizes this as 'Türkiye challenges Cyprus's EEZ'. The documents show a more specific pair of claims: a bilateral delimitation based on UNCLOS, against a Turkish claim based on equity, coastal length and the political equality of the two communities. Readers should check each side's own filings, as set out in the Editorial Principles. The sister fact check The Nations Compass: Fact Check: Is Türkiye Violating UNCLOS in the Eastern Mediterranean? addresses the UNCLOS claim.

Key Terms & Related Guides

• EEZ (Exclusive Economic Zone): A zone up to 200 nautical miles (about 370 km) from the baselines in which the coastal state has sovereign rights over resources.
• Continental shelf: The seabed and subsoil extending from the coast; rights exist ipso facto and do not depend on proclamation.
• Median line / equidistance: A line every point of which is equally distant from the nearest points of the two coasts; one method, not a mandatory rule.
• Principle of equity (hakkaniyet ilkesi): The doctrine that delimitation must reach an equitable result considering geography and proportionality.
• Note verbale: A formal diplomatic note, here sent to the UN Secretary-General to record objections.
• Blue Homeland (Mavi Vatan): Türkiye's doctrine of maritime jurisdiction in the Black Sea, Aegean and Mediterranean.

Related reading: Text & Territory home, UN Security Council Resolution 186 (1964) on the status question, The Worldlogue on islands and the continental shelf, and Regional Balance on the Cyprus issue.

Perspective Note

Text & Territory presents Türkiye's official perspective on the issues covered and explicitly distinguishes between that perspective and independent commentary. All claims are anchored in primary sources such as treaty texts, UN documents, archival records and official statements, which are cited so that readers can verify them. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources. This article is published by the Text & Territory Editorial Team.

• The Treaty Line: UN Security Council Resolution 186 (1964): Reading the Text and the 'Government of Cyprus' Question — Read UN Security Council Resolution 186 (1964) on Cyprus: what it says, how UNFICYP began and why Ankara disputes the 'Government of Cyprus' label.