When I tell people about Istanbul’s tunnels, they usually expect a story about the Marmaray Project, the 13.6 km long rail link between Asia and Europe under the Bosporus. Inaugurated in 2013, the tunnel is an impressive feat of engineering. There is a great video on YouTube.
Blue Mosque in Istanbul and the neighbourhood where once the Imperial Palace stood
My story is different though. It refers to medieval rumours that Byzantine monks had secretly dug tunnels below Constantinople during the siege of 1453. Fearing that the Ottoman Sultan would melt down all church treasures and mint money, the monks intended to hide the religious artefacts for good. Some of these precious religious items had already been shipped to Venice under Cardinal Bessarion, including his famous collection of books which would form the core of the world’s first public library. But most church treasures stayed in Constantinople. There were simply too many.
There are indeed hundreds of hidden structures below today's Istanbul but no secret tunnels
The story of the secret tunnels circulated widely in Christian Europe. Anybody who would liberate Constantinople from the Turks would be rewarded with these riches. Never mind that these treasures belonged to the church. The hopeful “liberators” would get them and use them as they pleased. Quite a contrast to the practice of the Ottoman Empire. By 1453, still more than half of the its population were Christians; the Sultans had a proven track record of religious tolerance and respect. With very few exceptions, churches were left untouched and Christians could continue their religious practice as before. Seems that the Ottomans were more cultivated than the Europeans ...
All these Turkish Houses below the Blue Mosque are built on Roman/Byzantine Foundations
Most rumors have a true core though. There are indeed large underground structures in Istanbul – although they are not tunnels. They were the foundations of old Constantinople. At the time of the siege, the town counted only 30’000 inhabitants and most of its public and private buildings were in an advanced state of decay. But Roman structures are sturdy. Whilst the upper floors collapsed, the foundations survived. Given the town’s depopulation, the Turkish Sultans brought in settlers from the entire Empire. By 1650, Constantinople was bigger than ever and had more than 700’000 inhabitants. Most of them were of Turkish origin but the Greek and Armenian minorities accounted for about 100’000 people each. All these new settlers built their homes on top of the Roman and Byzantine ruins.
This old Cistern from the 6th century AD is used today as a Jewellery Factory
The new homeowners knew - of course - about their “roman” cellars. They not only provided a stable platform for the new building. They were also excellent storing facilities. Dry and cool, they could store almost any good. Like in Italy, a business was a family affair. Work and private life were not separated but happened under the same roof. As we have seen in Venice, people lived on the upper floors and worked in the basement or on the ground floor. The separation of working from living places happened only during the industrial revolution.
Some of the Caves are used as Storage Rooms; they are cool and dry
Until 1980, the home owners in Istanbul kept quiet about what was below their houses. Under Turkish Law any antique object was state property, regardless of whether found on public or private property. Nobody wanted to have the state in their home digging up the cellar. The law changed however in 1980 and made people the owner of any object found on their property. Not surprisingly, the home owners started to open up.
Professor Ozgumus (checkered shirt),an Archeologist from Istanbul, searched in his home town for ancient remains for over 20 years
Today, we know about 300 sites and can safely assume that there are thousands more. The discovery and documentation of these underground structures must be credited to Feredun Ozgumus, a 65-year-old archeology professor at the University of Istanbul. For more than 20 years, Ozgumus knocked on the doors of Istanbul’s oldest neighborhoods and asked to see the basement. Sometimes, they are full of debris, sometimes they are used for business.
When walking towards the Roman Palace mosaics on the Blue Tour, we are passing a carpet shop where we must stop. In its mids stand two antique columns which the owners carefully preserved and restored. The exciting part of all these recent findings is the fact that they show a world most people believed was lost. Archeologists know relatively little about Constantinople since it was so quickly overbuilt. With access to the ancient caves, we now finally learn about daily life in the Byzantine Empire. The tunnels of Istanbul finally yield the treasures promised for centuries. Albeit they are different in natue.
Byzantine pots, plates and amphorae found in one of these underground structures