Basilica Cistern, Istanbul, photo Diego Delso, 28 September 2024, delso.photo, CCA-SA 4.0 International license. The controversial transfer of the Basilica Cistern, a World Heritage Monument and top-ranked Istanbul tourist attraction, from the opposition-controlled metropolitan municipality to Turkey’s General Directorate of Foundations is more than a dispute over a tourism venue. The transfer was part of the Erdoğan government’s attempt to discipline municipal authorities, who are often dominated by opposition parties, and to exploit the unstable legal status of religious foundations, vakif, pl.vakiflar. The transfer of the already well-managed Basilica Cistern is the latest offensive in the Turkish state’s history of using foundation law to appropriate or control minority religious property.
Basilica Cistern, Medusa Head at base of pillar, photo Diego Delso, 28 September 2024, delso.photo, CCA-SA 4.0 International license.
In April 2026, the Istanbul Metropolitan Municipality, or İBB, discovered that the cistern’s title had been registered to foundations administered by the General Directorate of Foundations, an agency of the Ministry of Culture and Tourism. The municipality said it had received no advance notification. State officials briefly took control of the Cistern in June, forcing municipal employees to remove their ticketing facilities. An appellate administrative court then suspended the eviction while the underlying title dispute continued. The cistern therefore remains in legal limbo rather than having been conclusively transferred.[1]
The political context is obvious. The İBB has been governed by the opposition Republican People’s Party since Ekrem İmamoğlu’s 2019 victory ended decades of rule by Erdoğan’s political movement in Turkey’s largest city. The municipality restored the cistern between 2020 and 2022 and developed it into one of Istanbul’s most successful cultural sites. Removing the monument from municipal control deprives the city administration of revenue and prestige while transferring authority over exhibitions, ticketing and historical interpretation to the central government. Opposition officials have described the action as part of a broader effort to strip elected municipalities of valuable property and institutional autonomy.
A Byzantine public work claimed through Ottoman law
The Basilica Cistern was constructed by Byzantine Emperor Justinian I in the sixth century beneath a grand public square(the Stoa Basilica) west of Hagia Sophia. It was not a church but an immense hydraulic installation built to collect aqueduct water and relieve Constantinople’s seasonal shortages.
‘Peacock column’ in the Basilica Cistern, Istanbul, photo Wiki Leylek, 10 October 2023, CCA-SA 4.0 International license.
The chamber measures approximately 138 by 65 meters and is supported by 336 columns, many reused from earlier Roman structures. Its celebrated Medusa-head bases are also examples of spolia, ancient repurposing of building materials. Some have speculated that their sideways and inverted positions were intended as a Christian rejection of pagan religion, but there is not evidence for this. During the Ottoman period, residents continued to obtain water through wells from houses above the cistern. The sixteenth-century visitor Pierre Gilles described traveling between its columns by boat while local inhabitants caught fish in the water.[2]
“Zonaras mentions nothing of the Form of the Basilica, which contain’d the Library, but only says, that it adjoin’d to the Chalcopratia, or Braziers Shops. Cedrinus calls the Basilica, Cisterna, which some Writers erroneously tell us, was built by Constantine the Great. I am confirm’d in this Opinion from Procopius, who says, that near the Imperial Portico, where the Lawyers used to plead, there was a spacious Building of a great Length and Breadth, encompassed with Pillars in a quadrangular Manner, situate on a rocky Ground, which was built by Justinian to a great Height, for preserving the Water in Summer, which was brought into it by subterraneous Pipes, and in the Winter from the Aqueducts, for the Use of the Poor.”
“…The Imperial Portico is not to be seen, though the Cistern is still remaining. Through the Carelesness and Contempt of every thing that is curious in the Inhabitants, it was never discover’d, but by me, who was a Stranger among them, after a long and diligent Search after it. The whole Ground was built upon, which made it less suspected there was a Cistern there. The People had not the least Suspicion of it, although they daily drew their Water out of the Wells which were sunk into it. I went by Chance into a House, where there was a Descent into it, and went aboard a little Skiff. The Master of the House, after having lighted some Torches, rowing me here and there across, through the Pillars, which lay very deep in Water, I made a Discovery of it. He was very intent upon catching his Fish, with which the Cistern abounds, and spear’d some of them by the Light of the Torches…”
Turkey’s iniquitous foundation laws
The government’s case rests on the claim that the cistern was later maintained or incorporated into several Ottoman vakıflar—pious or charitable foundations—and therefore must now be administered for their historical purposes.
That argument was strengthened by Law No. 7565, adopted in November 2025. The amendment broadened Article 30 of the Foundations Law so that a cultural property may be treated as foundation property when foundation resources were used in its construction, repair or enlargement, even where the original endowment documentation is incomplete.[3]
This creates a serious historical problem. Ottoman maintenance is an authentic part of the cistern’s history, but maintenance is not creation. A later Muslim foundation’s contribution does not alter the fact that the monument was built roughly nine centuries before the Ottoman conquest as a Byzantine civic water system. The new legal approach risks allowing a later layer of religious patronage to displace both the monument’s original identity and the long-established rights of the city that maintained it.
A precarious foundation system
Turkey’s vakıf system contains a fundamental contradiction. Foundation property is not, in principle, ordinary state property. It is dedicated to an institutional, charitable or religious purpose. Yet the General Directorate of Foundations registers, supervises, audits and, in some cases, directly administers it.
Fener Greek Boys High School, photo Ragnhild&Neil Crawford, 16 October 2016. CCA-SA 2.0 Generic license. This was the oldest continuing Greek-Orthodox educational institution in Istanbul, established in 1454, the current building built in 1881-1883. In October 2025, the Turkish Ministry of Education notified the school that it must vacate its premises within 90 days due to not meeting new earthquake reinforcement standards.
This dependence is especially consequential for non-Muslim communities. Under the 1935 Law on Foundations, pre-republican Greek Orthodox, Armenian, Jewish and other communal institutions were converted into “community foundations” and registered through declarations submitted in 1936.[4] Churches, patriarchates and other faith communities do not themselves possess full legal personality. They must own their churches, schools, hospitals and cemeteries through separate foundations, associations or other legal entities.
The result is a fragmented structure in which each church, cemetery, school or hospital may be controlled by a different foundation board, while the community’s religious leadership cannot necessarily own or manage the community’s assets as a whole. The Directorate itself states that new community foundations cannot be established under the Civil Code and that existing foundations remain subject to its supervision.
The system is formally neutral but substantively unequal. Mainstream Sunni Muslim institutions benefit from the Directorate of Religious Affairs, or Diyanet, which is integrated into the state and handles the administration and representation of mosques and religious personnel. Non-Muslim communities cannot rely on the Diyanet and must instead operate indirectly through state-supervised foundations.
A history of confiscation and partial restitution
The dangers of this arrangement are very real. In 1974, Turkey’s Court of Cassation treated the 1936 declarations as limiting the property that community foundations could own. Properties acquired by minority foundations after 1936 were returned to former owners or registered to the Treasury, the General Directorate of Foundations or third parties. The Directorate’s own historical account acknowledges this process.
Map of Constantinople around 1420, made by Florentine cartographer Cristoforo Buondelmonti, from the volume Liber insularum archipelagi. The Church of Peribleptos is the domed building on the lower left part of the map. Public domain.
The European Court of Human Rights subsequently found violations of the right to peaceful enjoyment of property in cases involving Greek Orthodox and Armenian foundations. These included the Fener Greek Boys’ High School Foundation, the Samatya Surp Kevork Armenian Church (where the Church of Peribleptos once stood), School and Cemetery Foundation, the Yedikule Surp Pırgiç Armenian Hospital Foundation and the Bozcaada Greek Orthodox Church Foundation.
Turkey has taken some corrective steps. A 2011 amendment allowed community foundations to seek the return of certain confiscated properties or compensation when restitution was impossible.[5] The government reports that hundreds of properties were subsequently returned and that a 2018 measure transferred 55 properties, including churches, monasteries and cemetery lands, to four Syriac foundations. These measures included property associated with the Mor Gabriel Monastery.
Those restitutions were significant, but they did not remedy the underlying defect. The same Directorate that supervises minority foundations—and historically received some of their confiscated property—also determines many restitution and administration questions. Religious communities still lack the independent legal personality needed to own and defend their collective property.
From religious and municipal rights to national claims
The Basilica Cistern is not a minority church or school and less likely to become a sort of Muslim center. But it is a profitable enterprise that was operated by a city government in opposition to Erdogan’s party and its loss is a loss to the city. But the history of foundation law changes how the transfer should be understood. A legal system that has repeatedly threatened Orthodox Christian, Armenian, and Jewish ownership is now being used expansively to remove a Byzantine monument from an elected city government and place it under a central agency invoking Ottoman Islamic endowments.
ramaic inscriptions over the portal of Mor Gabriel monastery in Midyat, Turkey. Photo Christian Koehn, August 2001, CCA-SA 2.0 Germany license.
The government can legitimately argue that Ottoman foundations helped preserve the structure and that foundation assets should be protected from neglect. Yet the institutional imbalance is clear. Sunni Islam is administered and financed through the central state, while non-Muslim institutions remain divided among vulnerable, closely supervised legal entities. In that setting, the use of vakıf law to reclaim major urban monuments naturally appears less like neutral conservation and more like intervention into city-managed public heritage.
The most immediate usurpation is political: authority is taken from Istanbul’s elected municipality after it restored and successfully operated the monument. The broader danger is cultural. Once control passes to the central government, it can determine whether the cistern is presented principally as Byzantine engineering, as an Ottoman foundation possession or as evidence of an uninterrupted Turkish-Islamic custodianship.
Basilica Cistern Interior with Medusa head column, photo Metuboy, 27 July 2022, CCA-SA 4.0 International license.
This an extension of a pattern that has already transformed major World Heritage Monuments of Christian origin like Hagia Sophia and the Chora Church into mosques. Beyond the serious physical damage that these transfers have already wrought on irreplaceable monuments of Byzantine heritage, the manipulation of their stories, their history and meaning, for purely political purposes is indefensible.
The issue is not whether the Ottoman history of the cistern should be suppressed. It should celebrated, together with its other cumulative histories. The issue is whether later Muslim patronage will be used to diminish Byzantine origin, override municipal rights and place another layer of Istanbul’s plural past within a centralized religious-national narrative.
The Basilica Cistern’s construction is an argument against exclusive ownership of its history. Roman materials were reused by Byzantine engineers; the reservoir was maintained in Ottoman Istanbul; and modern municipal conservators transformed it into a public museum. Its preservation depends on recognizing all of those layers. The Erdoğan government’s transfer threatens to turn stewardship into narrative possession—the power not only to administer the monument, but to decide which civilization may claim it.
Cultural Property News expresses its thanks to Hazel Levent, Ece Akıncıbay, Ayris Açıkalın, Zeynep Ülkü Kahveci of White & Case LLP, the authors of the Global Art and Heritage Law Series volume Turkey, for their analysis of Turkey’s vakif foundation laws. The Global Art and Heritage Law Series is an initiative of the Committee for Cultural Policy, Inc. in collaboration with TrustLaw, the Thomson Reuters Foundation’s global, legal pro bono service that connects law firms and legal teams to non-governmental organizations and social enterprises that are working to create social and environmental change.
ADDITIONAL READING
Turkey – Hagia Sophia Suffers Serious Damage: Walls Peeled and Marble Tiles Shattered, Cultural Property News, July 1, 2022.
Turkey Claims all Art and Artifacts: Centuries of Multicultural History and Trade Denied, Cultural Property News, January 7, 2020.
Turkish MoU Will Devastate Minorities, Bolster Erdoğan Regime, Cultural Property News, July 1, 2021.
NOTES
[1] The Istanbul Regional Administrative Court, Eighth Administrative Litigation Chamber, issued a stay order on June 4, 2026.
[2] Pierre Gilles, The Antiquities of Constantinople, bk. 2, ch. 20. (THE Antiquities
OF CONSTANTINOPLE. With a Description of its SITUATION, the Conveniencies of its
PORT, its PUBLICK BUILDINGS, the Statuary, Sculpture, Architecture, and other CURIOSITIES of that CITY. With Cuts explaining the Chief of them. In Four Books.
Written Originally in Latin by Petrus Gyllius a Byzantine Historian. Now Translated into English, and Enlarged with an Ancient Description of the Wards of that CITY, as they stood in the Reigns of Arcadius and Honorius. by John Ball, London, 1729)
[3] Law No. 7565 (2025), art. 11, amending Foundations Law No. 5737, art. 30.
[4] Foundations Law No. 2762 (1935); 1936 Declarations.
[5] Foundations Law No. 5737, provisional art. 11.
