The Republic of Turkey was proclaimed on 1923-10-29, and the state’s political center shifted from Istanbul to Ankara. This change reduced Istanbul’s role as an imperial seat and reframed the city as a major port and commercial center of a nation-state. Urban decisions increasingly balanced modernization goals with what to do with Ottoman-era institutions, monuments, and neighborhoods.
In 1924, Topkapı Palace—long a central Ottoman administrative and court complex—was turned into a museum. This signaled a new approach to Ottoman spatial heritage: key imperial sites would be preserved and reinterpreted for the public rather than used for governance. The conversion also helped anchor the Historic Peninsula as a cultural core even as the city modernized.
Turkey’s Municipal Law No. 1580 (1930) helped define how municipalities would be organized and what responsibilities they would carry. For Istanbul, this mattered because large-scale planning and public works required a stronger municipal framework. It also shaped how the city could regulate development that affected historic neighborhoods and monuments.
A Turkish government decision ended Hagia Sophia’s use as a mosque and reopened it as a museum on 1935-02-01. This was a high-profile example of how the early Republic managed Ottoman-Islamic monumental space by recasting it as national and world heritage. The decision influenced conservation priorities and public access in the historic core of Istanbul.
In 1936, French planner Henri Prost was brought in to develop a comprehensive plan for Istanbul. His work aimed to improve circulation and public spaces while also highlighting major monuments, but it often required cutting new roads through dense historic fabric. The invitation marked a turning point toward centrally guided, master-plan urban transformation.
Prost’s early master plan work (often dated to 1937) laid out new boulevards, parks, and zoning ideas for the city. It introduced a modernization logic that prioritized traffic flow and monumental vistas, reshaping how Ottoman-era neighborhoods were valued and altered. Later projects—especially in the 1950s—often drew on this planning framework.
In 1940, the Taksim Military Barracks were demolished as part of the redesign of Taksim Square area under Prost-era planning. The clearance replaced a large Ottoman-era military structure with a modern civic space vision that emphasized open squares and greenery. This showed how some Ottoman structures were removed to create new public spaces aligned with Republican urban ideals.
Gezi Park was completed in 1943, becoming a prominent green space next to Taksim Square. The project reflected a wider planning goal: providing parks and promenades while reorganizing dense urban areas. It also highlighted tensions between building a modern city and the loss or relocation of older land uses and communities within historic districts.
In 1951, Turkey constituted the High Council of Real Estate Antiquities and Monuments (a national body for heritage decisions). This institutional step mattered because it created a more formal system for evaluating, registering, and approving interventions in historic buildings and sites. It became a key arena where modernization projects and conservation demands were negotiated.
On 1955-09-06 to 1955-09-07, widespread attacks targeted minorities in Istanbul, damaging homes, businesses, churches, and cemeteries. Beyond the immediate violence, the events weakened communities that had maintained parts of the city’s multi-ethnic Ottoman-era urban life, especially in areas like Beyoğlu. The aftermath contributed to demographic change and the shifting use and care of many buildings and neighborhoods.
Beginning in 1956–1957, major road projects such as Vatan Avenue were opened, involving wide-scale demolition and rebuilding. These projects expanded earlier planning ideas but executed them at larger scale, reshaping Ottoman street patterns and displacing residents. They also changed how key monuments were approached and seen, often improving access while reducing historic fabric around them.
In 1973, Turkey adopted the Act on Antiquities (Law No. 1710), replacing older Ottoman-era legal foundations for protecting antiquities. The law strengthened the statutory basis for controlling changes to historic sites and monuments, including many Ottoman-era structures in Istanbul. It set a legal backdrop for late-1970s planning debates about growth, infrastructure, and conservation.
In 1985, UNESCO added the “Historic Areas of Istanbul” to the World Heritage List, including major zones on the Historic Peninsula such as Sultanahmet, Süleymaniye, Zeyrek, and the Land Walls. Although this is just after the 1923–1980 period, it reflects the long-term outcome of earlier decades of urban change: international attention increased for conserving the city’s layered Byzantine and Ottoman heritage. The listing helped frame future management as both a local responsibility and a global concern.
Istanbul's urban transformation and management of Ottoman spatial heritage (1923–1980)