The most famous dome in İstanbul is currently under a sheet. Workers began covering the temporary steel roof above Hagia Sophia's main dome this week, and the Culture and Tourism Ministry picked the colour with some care: grey, to sit quietly against the lead it is hiding.
The date was chosen too. The announcement came on 24 July, six years to the day since the building reopened for Friday prayers as a mosque.
Underneath the sheeting is the part of the story that will outlast the anniversary. Surveys of the building found that the main dome needs strengthening. To do that, the lead covering has to come off and be repaired or replaced, and the mosaics on the inner face of the same dome have to be conserved at the same time, from the other side of the shell. Hence the steel roof, and now the canvas.
Working on a building that will not close
The constraint shaping all of this is that Hagia Sophia stays open. It is a working mosque with a congregation, and, by the İstanbul deputy mufti Arif Cevlek's account to Anadolu Agency, it has taken more than 30 million visitors since 2020. That figure is his and has not been independently audited, but anyone who has seen the summer queues on the square will not find it hard to believe.
So the engineering has been built around not stopping. A steel platform 43.5 metres (143 feet) high stands inside so prayers continue below the works. A tower crane serves the dome from outside. Scaffolding, safety mesh and the temporary steel frame carry the job, and Hürriyet Daily News reports that non-original cement plasters applied by earlier repairs are being stripped back and replaced with traditional Ottoman materials.
The ministry says a scientific committee of academics and conservation specialists picked the covering itself. It is flame-retardant to the highest standard available, and before anyone put it up, the engineers ran the weight and wind-load numbers against what the temporary steel frame could carry and what the dome below could take. This is the sort of detail that sounds like bureaucratic throat-clearing until you remember what happens if a tarpaulin the size of a building catches the Bosphorus wind.
What the dome is actually being protected from
Culture and Tourism Minister Mehmet Nuri Ersoy has been plain that earthquake readiness is the point. İstanbul sits on a fault that seismologists have spent two decades warning about, and the dome is the piece of Hagia Sophia with the least margin when the ground moves.
That threat is decades old, and the clearest record of it belongs to UNESCO, whose files have tracked this dome since the 1980s.
Hagia Sophia has been part of the Historic Areas of Istanbul, inscribed as a World Heritage site in 1985, for 41 years. Go through the World Heritage Committee's files and the same building keeps appearing. In 1991 the World Heritage Fund approved 20,000 dollars for "restoration works of the mosaics of the dome." More money followed for the mosaics in 1994 and again in 1998. UNESCO and ICOMOS sent monitoring missions through the 1990s, and in 1999 the Committee pressed for a standing international scientific committee on the building.
Then, at the Committee's session in Marrakesh in late 1999, Türkiye's own representative reported that the August earthquake that year had left "minor cracks in several historic monuments including the Hagia Sophia."
That was 27 years ago. The dome now going under canvas is the same dome whose mosaics UNESCO money helped restore in 1991, and the cracks reported in 1999 were the early notice. What is happening this summer is the answer to a warning that has been sitting in the file since before most of today's visitors were born.
The anniversary itself
The legal sequence behind the date is short. On 10 July 2020 the Council of State annulled the 1934 cabinet decree that had turned the mosque into a museum, a status it had held for 86 years. Erdoğan signed a decision the same day transferring the building to the Presidency of Religious Affairs. The first Friday prayers followed on 24 July 2020.
Before that it had been a mosque since 1453, when Mehmed II converted it through his endowment after the conquest, and, before the conquest, a church for more than nine centuries.
The decision drew criticism abroad at the time, and Cevlek addressed it directly, arguing that the visitor numbers since have answered the objection that there was no need to reopen the building for worship. He also said pilgrimage tours from Uzbekistan, Malaysia and Indonesia increasingly route through İstanbul, and that around 120 staff work the building daily.
The political statements read the day the way the government has read it since 2020. Erdoğan called the reopening a blessing and described Hagia Sophia as a work apart in its architecture and its standing in the world. Communications Director Burhanettin Duran went furthest, casting the 2020 decision as an expression of "the nation's will to independence" rather than a change of legal status, the frame that turns a building's paperwork into a sovereignty statement. Ersoy, for his part, announced the restoration phase on NSosyal, the state-backed Turkish alternative to X, calling the building an inheritance from Mehmed II.
The anniversaries will keep coming annually and the statements with them. The dome is the part with a deadline, and it is not set by any calendar in Ankara.