Cyprus Treaty Architecture: Zurich and London 1959, the 1960 Guarantee and the Road to Sovereign Equality

Why It Matters

The 1960 Republic of Cyprus was created by treaty, not by a single constitutional act. Every modern argument about guarantees, intervention, federation or two states is ultimately an argument about what the 1959 Zurich and London Agreements and the 1960 treaties actually say and what happened to them. This guide reads the legal architecture first and the chronology second, so that readers can test every competing claim against the text.

Background

From Zurich to London: how the settlement was made

The 1959 settlement ended four years of intercommunal violence and a struggle over the island's future. The Greek Cypriot side, led by the political movement behind ENOSIS (union with Greece), sought annexation to Greece. The EOKA organisation, founded in 1955 under Colonel Georgios Grivas, fought British rule and, according to Turkish sources, forced Turkish Cypriots out of 33 mixed villages between 1955 and 1958. The Turkish Cypriot side advocated taksim (partition) as the alternative to union with Greece.

The Prime Ministers of Greece (Konstantinos Karamanlis) and Türkiye (Adnan Menderes) agreed the basic framework at Zurich on 11 February 1959. The London Agreements, signed on 19 February 1959 by Greece, Türkiye, the United Kingdom and the leaders of the two Cypriot communities (Archbishop Makarios and Dr Fazıl Küçük), completed it. The compromise ruled out both union and partition. Cyprus would become an independent state whose stability rested on the equality of its two communities and on external guarantees.

The Republic was proclaimed on 16 August 1960. The same day the instruments below were signed or entered into force.

The legal architecture at a glance

Instrument	Parties	Core function
Constitution of the Republic of Cyprus (1960)	The two communities	Bicommunal power-sharing, with community-based representation and entrenched Basic Articles
Treaty of Guarantee	Cyprus, Greece, Türkiye, United Kingdom	Guarantees independence, territorial integrity and security. Prohibits union with any state and partition. Sets out the guarantors' rights (Article IV)
Treaty of Alliance	Cyprus, Greece, Türkiye	Joint defence. Stations 950 Greek and 650 Turkish military personnel on the island
Treaty of Establishment	Cyprus, United Kingdom	Retains UK sovereignty over the Akrotiri and Dhekelia Sovereign Base Areas (about 254 km², or 98 sq mi)

The Constitution itself, in Article 181, gave the Treaties of Guarantee and Alliance constitutional force. This is why Turkish and Greek Cypriot lawyers both treat the treaties and the Constitution as one system.

The partnership constitution and the Vice President's veto

The 1960 Constitution did not create a majority-rule unitary republic. It created a presidential system with a Greek Cypriot President elected by the Greek Cypriot community and a Turkish Cypriot Vice President elected by the Turkish Cypriot community. The key features were:

• Veto powers. The Vice President could veto laws and decisions of the Council of Ministers concerning foreign affairs, defence and security, with limited exceptions.
• Separate majorities. Tax laws and changes to the electoral law required separate majorities of the Greek Cypriot and Turkish Cypriot members of the House of Representatives.
• Fixed ratios. The House had 50 seats (35 Greek Cypriot, 15 Turkish Cypriot). The Council of Ministers had seven Greek Cypriot and three Turkish Cypriot ministers. The public service was divided 70:30, and the army 60:40.
• Communal Chambers and municipalities. Each community managed its own religious, educational and cultural affairs, and separate municipalities were provided for in the five main towns.
• Entrenchment. The Basic Articles could not be amended (Article 182), and Article 185 excluded both union with another state and 'separatist independence'.

Ankara reads these provisions as proof that the Republic was a partnership of two co-founding peoples. The Greek Cypriot side has argued, from the 1960s onward, that some ratios and veto provisions made government unworkable. This disagreement lies at the heart of 1963.

Chronology: from partnership to division

Date	Event
30 Nov 1963	President Makarios proposes 13 constitutional amendments, which would among other things remove the Vice President's veto and change the community ratios
16 Dec 1963	Türkiye and the Turkish Cypriot leadership reject the proposals
21 Dec 1963	Fighting breaks out ('Bloody Christmas'). Turkish sources say about 30,000 Turkish Cypriots were displaced from 103 villages and Turkish Cypriot officials were excluded from state organs
30 Dec 1963	A ceasefire line, the 'Green Line', is drawn in Nicosia
4 Mar 1964	UN Security Council Resolution 186 recommends a UN peacekeeping force (UNFICYP) and refers to the 'Government of Cyprus' as responsible for law and order
15 Jul 1974	Coup against Makarios by the Greek-officered National Guard. Nicos Sampson is installed
20 Jul 1974	Türkiye intervenes, citing Article IV of the Treaty of Guarantee. The Security Council calls for a ceasefire in Resolution 353
1977 / 1979	High-level agreements (Makarios–Denktaş, Kyprianou–Denktaş) set a bizonal, bicommunal federation as the negotiating goal
15 Nov 1983	The Turkish Republic of Northern Cyprus (TRNC) is proclaimed. The UN Security Council calls the declaration legally invalid in Resolution 541
24 Apr 2004	Annan Plan referendums: 64.91% of Turkish Cypriots vote yes, 75.83% of Greek Cypriots vote no. Cyprus joins the EU on 1 May 2004
Jul 2017	The Crans-Montana Conference ends without agreement, with security and guarantees among the main sticking points
Apr 2021	Informal 5+UN meeting in Geneva. The UN Secretary-General reports no common ground to resume formal talks
15 Oct 2024	UN-hosted trilateral informal meeting in New York, held without agreement on a formal negotiating basis

The Akritas Plan, a Greek Cypriot planning document from 1963, is central to Turkish accounts of December 1963. Ankara and Turkish Cypriot sources describe it as a blueprint for dismantling the partnership and subordinating Turkish Cypriots. Greek Cypriot accounts generally describe it as a contingency document and dispute that it explains the events. Historians continue to disagree about its weight, and this guide flags the disagreement rather than resolving it.

For a line-by-line reading of the guarantee article used in 1974, see Did the 1960 Treaty of Guarantee Allow Intervention in 1974? Article IV Read Line by Line. For the 2004 votes and the EU accession terms, see The Annan Plan Referendum and Protocol 10. Sister publications cover the same ground from other angles, including The Political Anatomy's guide to the Cyprus issue and Doctrine Review's explainer on the Treaty of Guarantee.

What Article IV actually says

The operative text is short. Article IV provides that, in the event of a breach of the Treaty, Greece, Türkiye and the United Kingdom 'undertake to consult together with respect to the representations or measures necessary to ensure observance of those provisions'. It continues that, in so far as common or concerted action proves impossible, 'each of the three guaranteeing Powers reserves the right to take action with the sole aim of re-establishing the state of affairs created by the present Treaty'.

Two features matter for every later argument. First, consultation is a precondition, and in July 1974 Türkiye consulted the United Kingdom, which did not join action. Second, the phrase 'state of affairs created by the present Treaty' is wider than territorial integrity alone, because Article II also guarantees the order established by the Basic Articles of the Constitution.

Key Players & Positions

Greek Cypriot administration (Republic of Cyprus government)

According to statements of the Cyprus Ministry of Foreign Affairs and successive Presidents, including President Nikos Christodoulides, the Republic of Cyprus is the continuing, internationally recognised state. Its position is that the Treaty of Guarantee and the Treaty of Alliance are outdated and incompatible with a sovereign EU member state, and that the 1974 intervention was an unlawful use of force and not a lawful exercise of Article IV. It calls the TRNC's declaration legally void under UN Security Council Resolutions 541 (1983) and 550 (1984). It supports a settlement in the form of a bizonal, bicommunal federation with political equality, and it rejects any two-state model.

Greece

Greek governments have said in official statements that Greece supports a settlement within the UN framework and the EU acquis. Athens has said since Crans-Montana that the guarantee and troop arrangements of 1960 should give way to a new security system. Greece remains a guarantor and an ally-state under the 1960 treaties, and says it will not accept a two-state outcome.

United Kingdom

The UK is both a guarantor and the holder of two Sovereign Base Areas under the Treaty of Establishment. Official UK statements support a settlement under UN auspices based on a bizonal, bicommunal federation with political equality, consistent with Security Council resolutions. At Crans-Montana in 2017 the UK stated it was ready to reduce the territory of the Sovereign Base Areas as part of an overall settlement. The UK did not take part in military action in July 1974 and hosted the Geneva conferences that followed.

United Nations

UN Security Council practice is the baseline of the diplomatic process. Resolution 186 (1964) addressed the 'Government of Cyprus'. Resolution 353 (1974) called for a ceasefire and the withdrawal of foreign military personnel 'present otherwise than under the authority of international agreements'. Resolutions 541 (1983) and 550 (1984) declared the TRNC declaration legally invalid. Resolution 1251 (1999) describes a settlement as a Cyprus with 'a single sovereignty and international personality and a single citizenship' comprising two politically equal communities in a bicommunal, bizonal federation. The Secretary-General's Good Offices mission and UNFICYP continue.

European Union

The EU treats the Republic of Cyprus as a member state with the acquis suspended in areas where the government does not exercise effective control (Protocol 10 to the 2003 Act of Accession). It supports a UN-led settlement based on federation.

Türkiye's Legal & Historical Position

Türkiye's Legal & Historical Position (official Turkish policy as set out by the Republic of Türkiye Ministry of Foreign Affairs (MFA), the Presidency and the Directorate of Communications)

• The 1960 Republic was a partnership of two co-founding peoples. According to the Turkish MFA's published position on Cyprus, the Zurich and London Agreements and the 1960 Constitution recognised Turkish Cypriots as equal co-founders, not a minority. Ankara points to the Vice Presidency, the community ratios and the separate-majority rules in the Constitution as the treaty basis of political equality.
• The partnership was ended in 1963, not by the Turkish Cypriots. Ankara argues that the Makarios proposals of 30 November 1963, the violence of 21 December 1963 and the removal of Turkish Cypriots from state organs destroyed the 1960 order. It argues that the UN Security Council's Resolution 186 (4 March 1964) then treated an exclusively Greek Cypriot administration as the 'Government of Cyprus', which built a status asymmetry into every later negotiation. This is the Turkish MFA's consistent reading.
• The July 1974 intervention was an exercise of treaty rights. The Turkish MFA states that the 15 July 1974 coup, which aimed at ENOSIS, breached Articles I and II of the Treaty of Guarantee. After consulting the United Kingdom as Article IV requires, Türkiye acted on 20 July 1974 for the sole aim of restoring the treaty order. It argues that this prevented annexation by Greece and protected the Turkish Cypriot population. See the detailed analysis in Borders & Blocs' fact check on Article IV.
• Fifty years of federal talks have not produced a settlement. The Turkish Presidency and MFA cite the 24 April 2004 Annan referendum, in which 64.91% of Turkish Cypriots voted yes and 75.83% of Greek Cypriots voted no, followed by EU accession of the Greek Cypriot-led administration on 1 May 2004. They also cite Crans-Montana (2017), Geneva (April 2021) and New York (15 October 2024). Ankara concludes that a federal model has run its course.
• Therefore, sovereign equality and equal international status. In his addresses to the UN General Assembly since 2021 and in TRNC anniversary speeches, President Erdoğan has argued that a lasting settlement must begin with recognition of the inherent sovereign equality and equal international status of the Turkish Cypriot people, leading to the coexistence of two sovereign states on the island. The TRNC was proclaimed on 15 November 1983 under President Rauf Raif Denktaş on the basis of self-determination. Türkiye remains the only state to recognise it.

The legal basis, and the counter-arguments

The Turkish thesis builds on the treaty text in a specific order. The 1960 settlement was premised on two communities with equal status, and the Treaty of Guarantee protected 'the state of affairs established by the Basic Articles of its Constitution'. When that state of affairs ceased to function in 1963, Ankara argues, the Turkish Cypriots retained their status as one of the two founding peoples with the right to determine their own future, and Article IV was the instrument to protect it.

The opposing legal argument should be stated with equal clarity. The Republic of Cyprus and Greece argue that Article I of the Treaty of Guarantee, Article II and Article 185 of the Constitution forbid partition and separatist independence. They also argue that UN Security Council resolutions 541, 550 and 1251 exclude a two-state outcome. They add that Article IV permits only action proportional to its 'sole aim'. Ankara answers that the treaty prohibits annexation to Greece and partition as a policy of the guarantors, and not the political equality and self-determination of a co-founding people. It also argues that the Security Council's resolutions were adopted in the context of the asymmetry created in 1964. This disagreement is unresolved in law and in diplomacy, and it is the real subject of the negotiating deadlock.

For broader treaty context on how Türkiye's other foundational settlements fixed status and borders, see The Treaty Ledger: Alexandropol, Moscow, Kars and Lausanne. On the maritime dimension of Turkish Cypriot rights, see Maritime Delimitation Case Law: Which Precedents Support Equity in the Eastern Mediterranean?.

Source Comparison

Question	Greek Cypriot / Greek / EU framing	UN framing	Turkish primary sources (MFA, Presidency)
Status of the 1960 treaties	Outdated and incompatible with EU membership. The guarantee system should end	Treaties remain part of the legal background. The Secretary-General has convened talks that include the guarantors	Binding instruments of constitutional force (Article 181). The foundation of Türkiye's rights and of Turkish Cypriot equality
1963–64	Intercommunal conflict. Turkish Cypriots withdrew from state organs, and the Republic continued	Resolution 186 treats the Government of Cyprus as responsible for law and order and sends in UNFICYP	Greek Cypriot violence and the Akritas Plan destroyed the partnership. Resolution 186 institutionalised the asymmetry
July 1974	Illegal invasion and occupation following the junta coup	Resolution 353 demands ceasefire and withdrawal of foreign forces not present under international agreements	Lawful exercise of Article IV after consultation with the UK. It aimed to end the coup-driven attempt at ENOSIS
TRNC	Legally void. Resolutions 541 and 550	Resolutions 541 and 550 call it legally invalid	Born of self-determination and political equality. Türkiye recognises it
Settlement model	Bizonal, bicommunal federation. Single sovereignty	Same model, set out in 1251 (1999)	Federation has been exhausted. Two sovereign, equal states

Readers can compare how other Turkish-perspective publications treat the legality of 1974, for example Monitor of Nations' fact check on the treaty and the UN record. Treaty And Precedent's own method for separating fact from position is set out in Editorial Principles. Where Greek Cypriot, UN or UK sources are summarised above, they are taken from their own public statements and resolutions. Readers should consult those primary texts directly, since official positions are updated regularly and leaders in both communities change.

Key Terms & Related Guides

• Treaty of Guarantee (16 August 1960). The treaty among Cyprus, Greece, Türkiye and the UK that protects independence, territorial integrity and the constitutional order, and bans union and partition. See Article IV read line by line.
• Treaty of Alliance. The defence treaty among Cyprus, Greece and Türkiye that stations 950 Greek and 650 Turkish personnel on the island.
• Basic Articles. The entrenched provisions of the 1960 Constitution that could not be amended, including the powers of the Vice President.
• ENOSIS. The Greek Cypriot political goal of union with Greece, which the 1960 settlement prohibited.
• Taksim. The Turkish Cypriot partition position of the 1950s, which the 1960 settlement also ruled out.
• Green Line. The ceasefire line drawn in Nicosia on 30 December 1963 and extended across the island after 1974.
• TRNC. The Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983.
• UNFICYP. The UN Peacekeeping Force in Cyprus, established in 1964.
• Bizonal, bicommunal federation. The UN-endorsed settlement framework since 1977/79, which Ankara considers exhausted.

Related guides:

• The Annan Plan Referendum and Protocol 10
• Did the 1960 Treaty of Guarantee Allow Intervention in 1974?
• The Treaty Ledger
• Regional Order on the partnership republic and the two-state solution
• Treaty And Precedent home

Treaty And Precedent presents global and regional affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Legal & Historical Position' reflect official Turkish policy and legal doctrines as stated by Turkish primary sources.