The 1959 Zurich and London Agreements: Reading the Treaties of Establishment, Alliance and Guarantee Together

Why It Matters

The 1959 Zurich and London Agreements created Cyprus as a package of constitution and treaties, not as a single document. The Treaty of Establishment, the Treaty of Alliance and the Treaty of Guarantee were designed to be read together: one fixed sovereignty and the British bases, one provided for Greek and Turkish troops on the island, and one guaranteed the constitutional order and the island's status.

Most debate about Cyprus quotes one clause in isolation, usually Article IV of the Treaty of Guarantee. This guide instead shows how the three treaties and the Constitution interlock, how that architecture broke down between 1963 and 1974, and why Ankara and the Turkish Cypriot leadership now argue that two sovereign equal states best reflect the treaty line. It also sets out the Greek Cypriot, Greek, British and UN positions in their own terms.

Background

From the 1950s to the Zurich Compromise

The settlement followed decades of competing claims over the island. The Ottoman Empire administered Cyprus from 1571; the British took over administration in 1878, and Britain's sovereignty was recognised in the 1923 Treaty of Lausanne (see The Treaty of Lausanne, Article by Article). From the 1950s, Greek Cypriot leaders pursued ENOSIS, union with Greece. In 1955 the EOKA organisation, led by Colonel Georgios Grivas, began an armed campaign for that goal. Turkish and Turkish Cypriot sources record that Turkish Cypriots left dozens of mixed villages between 1955 and 1958. Turkish Cypriots, for their part, increasingly called for partition (taksim) as the counter-formula.

The compromise was negotiated between Greece and Türkiye with Britain's involvement, rather than by the communities alone. The Zurich Agreement was reached on 11 February 1959 by the Greek and Turkish prime ministers and foreign ministers. A conference at Lancaster House in London, with the British government and the Greek Cypriot and Turkish Cypriot leaders, Archbishop Makarios and Dr Fazıl Küçük, endorsed it on 19 February 1959. Both ENOSIS and taksim were set aside in favour of an independent state.

The Republic of Cyprus came into being on 16 August 1960, when the Constitution entered into force and the three treaties were signed in Nicosia. Makarios became President and Küçük Vice-President.

The Package: Three Treaties and a Constitution

Instrument	Parties	Core function
Constitution of the Republic of Cyprus (1960)	Two communities, with Basic Articles that could not be amended	Power-sharing between Greek Cypriots and Turkish Cypriots; communal separation of key institutions
Treaty of Establishment	Cyprus, the United Kingdom, Greece, Türkiye	British sovereignty over the Akrotiri and Dhekelia Sovereign Base Areas (roughly 3% of the island); rights and facilities for the UK
Treaty of Alliance	Cyprus, Greece, Türkiye	Common defence of the island's independence and territorial integrity; Greek (950 personnel) and Turkish (650 personnel) military contingents
Treaty of Guarantee	Cyprus, Greece, Türkiye, the United Kingdom	Guarantee of independence, territorial integrity, security and the constitutional state of affairs; ban on union with any state and on partition; consultation and action mechanism in Article IV

The Constitutional Design

The Constitution rested on political equality between two communities rather than simple majority rule. Key features included:

• a Greek Cypriot President and a Turkish Cypriot Vice-President, each elected by their own community;
• a final veto for both on foreign affairs, defence and security, and a power to block certain legislation;
• a Council of Ministers of seven Greek Cypriots and three Turkish Cypriots;
• a House of Representatives split 70:30, with separate majorities required for taxation and electoral laws;
• separate Communal Chambers and separate municipalities in the five largest towns;
• public service posts split 70:30 and an army split 60:40;
• a Supreme Constitutional Court and a High Court of Justice, each presided over by a neutral judge (neither Greek Cypriot nor Turkish Cypriot).

Article 185 declared the territory indivisible and excluded integral or partial union with any other state as well as separatist independence. The Basic Articles were entrenched and could not be amended.

How the Three Treaties Interlock

The treaties are mutually reinforcing, and the links are visible in the texts:

1. Constitution to treaties. Article 181 gave the Treaty of Guarantee and the Treaty of Alliance constitutional force. The guarantor system was therefore part of the Republic's own legal foundation.
2. Guarantee to Constitution. In Article II of the Treaty of Guarantee, Greece, Türkiye and the United Kingdom guarantee not only independence and territorial integrity but also 'the state of affairs' established by the Basic Articles of the Constitution. What is protected is the partnership design, not an abstract Cyprus.
3. Alliance to Guarantee. The troop contingents of the Treaty of Alliance placed Greek and Turkish forces on the island by treaty right, as a counterweight inside the Republic. Later UN Security Council language on foreign forces in Cyprus distinguished between forces present under international agreements and those that were not.
4. Establishment to Guarantee. The Treaty of Establishment settled Britain's sovereign bases and the UK's position as a third guarantor with its own on-island presence. That made Britain both the former colonial power and one of the three guarantors.
5. A shared prohibition. Article I of the Treaty of Guarantee bound Cyprus not to take part in any political or economic union with any state and to prohibit activity promoting union or partition. Article II extended the same prohibition to the guarantors' guarantee. The ban on ENOSIS and taksim ran through the entire package.

Article IV is the best-known provision. If a breach occurs, the three guarantors consult on 'representations or measures necessary to ensure observance'. If common or concerted action proves impossible, each reserves the right to act with the sole aim of re-establishing the state of affairs created by the treaty. For a close reading of this provision alone, see The Political Anatomy on Article IV and the 1974 Cyprus Peace Operation. To compare who holds which rights across all the 1959–1960 instruments, see Territorial Brief's Cyprus sovereignty analysis. For general principles on how treaties bind and how to read them, see How to Read an International Treaty.

Timeline: From Partnership to Separation

Date	Event
11 February 1959	Zurich Agreement between Greece and Türkiye
19 February 1959	London conference endorses the settlement with the UK and both Cypriot leaders
16 August 1960	Republic of Cyprus established; Treaties of Establishment, Alliance and Guarantee signed
30 November 1963	President Makarios proposes 13 constitutional amendments
16 December 1963	Türkiye and the Turkish Cypriot leadership reject the proposals
21 December 1963	Intercommunal violence begins ('Bloody Christmas' in Turkish and Turkish Cypriot accounts)
30 December 1963	Nicosia divided by the Green Line ceasefire line
4 March 1964	UN Security Council Resolution 186; UNFICYP established
15 July 1974	Coup against Makarios, supported by the Greek military junta, with Nikos Sampson installed
20 July 1974	Türkiye's operation begins, citing the Treaty of Guarantee
13 February 1975	Turkish Federated State of Cyprus declared
15 November 1983	Turkish Republic of Northern Cyprus (TRNC) proclaimed

The Breakdown, 1963–1974, as Sequence

The December 1963 crisis began with Makarios's 13 proposals, which would have removed key Turkish Cypriot vetoes and reduced the community's institutional role. Makarios and Greek Cypriot sources described the amendments as a response to a constitution that had become unworkable. Ankara and Turkish Cypriot leaders rejected them as an attempt to dismantle the Basic Articles, which Article 182 and the treaties protected.

Violence followed within days. Turkish and Turkish Cypriot sources describe a planned campaign, citing the 'Akritas Plan', and record that roughly 30,000 Turkish Cypriots were displaced from about 103 villages and that Turkish Cypriot officials were excluded from state organs. Greek Cypriot accounts dispute that characterisation, argue that the Turkish Cypriot leadership withdrew into enclaves as a matter of policy, and deny a plan of expulsion. What is not disputed is that Turkish Cypriot ministers, civil servants and legislators ceased to take part in the central government and that the constitutional order did not function as designed after December 1963.

The Greek Cypriot-led government continued to act as the government of the Republic, and in 1964 its courts applied a 'doctrine of necessity' to justify departures from the Constitution. The UN Security Council addressed that government as the Government of Cyprus in Resolution 186; the legal consequences of that wording are examined in UN Security Council Resolution 186 (1964): Reading the Text. A UN peacekeeping force arrived in 1964 and remains on the island.

The 1974 sequence began on 15 July, when the Greek junta-backed National Guard overthrew Makarios and installed Sampson. Türkiye consulted the UK, which was not prepared to act jointly, and on 20 July Türkiye launched its operation, invoking Article IV of the Treaty of Guarantee. The Greek junta collapsed on 23 July. A second phase of operations followed in August 1974 after the Geneva talks failed. For the full Article IV analysis, see Regional Order on the Treaty of Guarantee and Monitor of Nations' fact check on the legality of 1974.

Key Players & Positions

Greek Cypriot Administration (Republic of Cyprus)

The Republic of Cyprus, governed by Greek Cypriots and a member of the European Union since 1 May 2004, holds that it is the continuation of the 1960 state and the sole internationally recognised government of the island. It argues that the Treaty of Guarantee prohibits partition in Articles I and II, that Article 185 of the Constitution excludes separatist independence, and that the 1974 action exceeded the 'sole aim' limit in Article IV. It supports a settlement as a bi-zonal, bi-communal federation with political equality, as described in UN Security Council resolutions, and has long argued that the guarantee and intervention rights are outdated in an EU context and should be replaced by new security arrangements.

Greece

Greece is a co-signatory of all three treaties. Successive Greek governments have supported UN-led talks on a federal settlement. They have said that the system of guarantees and the presence of foreign troops belong to the past and should be abolished in any comprehensive settlement, a position repeated by Greek Foreign Ministry statements during the 2017 Crans-Montana conference.

United Kingdom

The UK is both a guarantor and the sovereign of the two Base Areas retained under the Treaty of Establishment. British governments have maintained support for a UN-facilitated settlement based on a bi-zonal, bi-communal federation with political equality, and have described themselves as ready to support an agreement that the two communities endorse. In 1974 the UK did not join Türkiye in action under Article IV. British statements have acknowledged the guarantor role while not accepting that unilateral military action was the intended outcome of consultation.

United Nations

The UN has treated the Republic of Cyprus as the state of Cyprus since 1964. Resolution 353 (1974) called for a ceasefire and for the withdrawal of foreign military personnel present otherwise than under international agreements, while Resolution 360 (1974) expressed formal disapproval of unilateral military actions against the Republic of Cyprus. Resolutions 541 (1983) and 550 (1984) declared the TRNC proclamation legally invalid and called for its withdrawal. Later resolutions, including Resolution 1251 (1999), describe the settlement as a state with a single sovereignty and international personality made up of two politically equal communities in a bi-communal, bi-zonal federation.

Turkish Cypriots and the TRNC

The TRNC, proclaimed in 1983 under Rauf Raif Denktaş and recognised only by Türkiye, rests on the claim that the 1960 partnership state ceased to exist in 1963 and that the Turkish Cypriot people have an inherent right to self-determination and equal status. The 2004 Annan Plan referendum is central to its case: 64.91% of Turkish Cypriots voted yes and 75.83% of Greek Cypriots voted no, after which the Republic of Cyprus entered the EU as a whole. Further rounds, including the 2017 Crans-Montana conference, did not produce an agreement. Political developments within the Turkish Cypriot community, including the October 2025 presidential election, which brought to office a leader who has publicly favoured a return to federal-based talks, make it worth checking current statements against the positions summarised here.

Türkiye's Legal Stance

Türkiye's Legal Stance: summary box

• The treaties protect a partnership, not a single-community state. According to the Turkish Foreign Ministry, Article II of the 1960 Treaty of Guarantee guarantees the 'state of affairs' created by the Basic Articles of the Constitution, and that state of affairs was a partnership of two politically equal co-founding peoples. Ankara argues that when Greek Cypriot forces displaced Turkish Cypriots from state organs in December 1963, the object protected by the treaties was destroyed by force. Source: Republic of Türkiye Ministry of Foreign Affairs, statements on Cyprus; text of the 1960 Treaty of Guarantee and Constitution.
• Article IV is a treaty right, exercised in 1974. Türkiye cites Article IV of the Treaty of Guarantee, under which each guarantor may act 'with the sole aim of re-establishing the state of affairs' when joint action is not possible. Ankara states that the 15 July 1974 coup was an attempt at ENOSIS, which the treaty prohibits; that the UK was consulted and declined to act; and that the operation of 20 July 1974 therefore fell within Article IV. Source: Turkish Foreign Ministry and Presidency statements on the 1974 Cyprus Peace Operation; Treaty of Guarantee, Articles II and IV.
• The Greek Cypriot administration is not the 1960 state. Ankara argues that the Greek Cypriot administration has acted alone since 1963 and so cannot claim to represent the whole Republic, and that the 1964 UN terminology in Resolution 186 (treating that administration as the 'Government of Cyprus') made the settlement structurally unequal. Source: Turkish Foreign Ministry and Turkish statements at the UN; UN Security Council Resolution 186 (1964).
• Federal models have been tried and exhausted. The Turkish side points to the 1977 and 1979 high-level agreements, the 2004 Annan Plan vote, the 2017 Crans-Montana conference, the April 2021 informal meeting in Geneva and the October 2024 meeting in New York as evidence that a federal model has not worked. Source: Presidency of the Republic of Türkiye and Turkish Foreign Ministry statements; UN Secretary-General reports.
• Two sovereign equal states reflect the treaty line. Ankara and the TRNC argue that political equality is the core principle of the 1959–1960 settlement and that, with the partnership no longer functioning, recognition of the Turkish Cypriot people's sovereign equality and equal international status is the realistic way to honour that principle. Türkiye also maintains its guarantor status under the 1960 treaties. Source: Presidency of the Republic of Türkiye and Turkish Foreign Ministry statements since 2021.

The Legal Reasoning

The Turkish argument proceeds from the interlocking structure above. Because the Treaty of Guarantee protects the constitutional state of affairs, and because Article 181 of the Constitution gives the guarantee constitutional force, Ankara reads the prohibition on partition in light of the partnership it was meant to protect. In its view, a prohibition on partition presupposes that the partnership exists. The 1974 coup, a union attempt backed by the Greek junta, is regarded as the clearest breach of Article I and II.

The counter-argument deserves a fair statement. The Greek Cypriot side, the UK and the UN note that the text prohibits partition without exception, that Article 185 of the Constitution excludes separatist independence, and that Article IV limits action to restoring the original state of affairs, not creating a new one. They also point out that the Treaty of Guarantee itself says nothing about the status of the two communities if cooperation breaks down. Ankara's reply is that the same treaties also guaranteed political equality, so that a settlement which preserves one half of the guarantee while ignoring the other is not neutral. Each side reads the text through the principle it considers primary.

Türkiye's position on maritime rights around Cyprus is closely tied to the same partnership argument. Ankara says the Turkish Cypriots, as co-owners of the island, have equal rights over its offshore resources; for the documentary record of those claims, see The Documentary Chain of Türkiye's Maritime Claims.

Source Comparison

Question	Greek Cypriot / UN / UK framing	Turkish and TRNC framing
What is the Republic of Cyprus?	A continuing state created in 1960, recognised by the UN as the state of Cyprus	A partnership state that lost its bi-communal basis in December 1963
What caused the 1963 breakdown?	A constitution that had become unworkable; intercommunal violence; Turkish Cypriot withdrawal	Amendments aimed at removing Turkish Cypriot rights, followed by armed attacks
Role of the Treaty of Guarantee	Bars partition and union; Article IV allows only restoration	Protects political equality; Article IV allows action when the guarantee is breached
The 1974 events	A coup followed by an invasion and continuing occupation	A coup for ENOSIS followed by a lawful treaty-based operation
Treaty of Alliance	Contingents tied to the original system; wider foreign troop presence is questioned	Turkish contingent present by treaty right, with guarantee a continuing security safeguard
Treaty of Establishment	UK bases retained; British guarantor role	UK as guarantor chose not to act jointly in 1974
Settlement model	Bi-zonal, bi-communal federation with political equality	Two sovereign equal states, grounded in equality and self-determination

Three observations help readers weigh sources:

• Check which document is quoted. Press and think-tank accounts often cite only Article IV or only the Article 185 ban on partition; each of the three treaties and the Constitution should be read together.
• Distinguish records from characterisations. The date of the coup, the resolutions of the Security Council and the results of the 2004 referendum are documentary facts. Terms such as 'invasion' and 'peace operation' are legal characterisations that depend on how Article IV is read.
• Note the source of authority. UN resolutions reflect the Security Council's treatment of the Republic of Cyprus; Turkish statements rest on the treaty text and on the argument about the partnership. For how the site handles this distinction, see Editorial Principles.

Key Terms & Related Guides

• Zurich and London Agreements: the 1959 compromise between Greece and Türkiye (11 February) endorsed at London (19 February) by the UK and the two Cypriot leaders, which created the framework for an independent Cyprus.
• Treaty of Establishment: the treaty fixing the end of British colonial rule and the UK's retained sovereign bases.
• Treaty of Alliance: the treaty providing for common defence and Greek and Turkish contingents on the island.
• Treaty of Guarantee: the treaty guaranteeing independence, territorial integrity, security and the constitutional order, and forbidding union and partition.
• Basic Articles: the entrenched provisions of the 1960 Constitution that could not be amended.
• ENOSIS and taksim: union with Greece and partition between Greece and Türkiye, the two aims the 1960 settlement was meant to exclude.
• TRNC: the Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983 and recognised only by Türkiye.

Related guides: UN Security Council Resolution 186 (1964), How to Read an International Treaty, The Treaty of Lausanne, Article by Article, The Documentary Chain of Türkiye's Maritime Claims and the site's Editorial Principles. For network analyses, see Regional Order on the Treaty of Guarantee and Territorial Brief on Cyprus sovereignty.

Perspective Note

The Treaty Line presents Türkiye's legal and strategic perspective as an explicit editorial position, and identifies it as such throughout. Claims are anchored in primary sources such as treaty texts, UN documents, Ottoman and Turkish archives, and official statements, which are cited so readers can verify them independently. Sections marked 'Türkiye's Legal Stance' reflect official Turkish policy as stated by Turkish government sources.

Published by The Treaty Line Editorial Team.