In older dictionaries of the Polish language, one can find the entry 'jedykuła', or 'jedykuł' in the sense of prison. The word comes from a fortress located in Istanbul. This fortress enclosed the ancient city walls of Constantinople, still from Byzantine times. The origins of this fortress can be traced to a triumphal arch from the 5th century AD, which in time came to be known as the Golden Gate. It is worth mentioning that Kyiv's Golden Gate, associated with the legend of Bolesław the Brave's entry into the city, takes its name from this former Constantinopolitan predecessor.

The fortress in Constantinople gradually began to grow. After the conquest of the capital of the Eastern Roman Empire by the Turks, Sultan Mehmed II the Conqueror added three defensive towers. Construction was completed in 1457. In Byzantine times, the towers were used as observatories, prisons or places of execution, while in the Ottoman period they were primarily used as prisons, treasuries or weapons depots. The five-sided frame of the fortress includes the following towers:

• Young-Smith Tower,
• Arsenal,
• Sultan Ahmet III Tower,
• Treasury,
• Dungeon (Inscription Tower),
• Cannon Tower (Virgin Tower),
• Flag Tower.

Of these, the Tower of Inscriptions is the most noteworthy. Due to the many years of restoration to which the entire fortress has gradually been subjected, it is unfortunately not possible at present to ascertain whether any inscriptions in Polish have survived, although this is not excluded and is even very likely. Primarily because of the many wars fought in the past by the Polish-Lithuanian Commonwealth and Turkey. Today it is still possible to see the barely visible inscriptions on the walls at the entrance to the tower, although they are not well legible, they are certainly not written in Polish. It is with this penitentiary function of the fortress that the history of the word jedykuła in Polish is connected. Among those imprisoned in Jedykuła were: the last Emperor of Trapezunt David II the Great Comnenus, the Georgian ruler Swimon I, Jerzy Chmielnicki (son of Bohdan Chmielnicki), the French diplomat Jan Baptysta de Lesseps (uncle of Ferdinand de Lesseps).

The most important Polish prisoner of Jedykuła, who spent about three years in these casemates, was Field Hetman of the Crown Stanisław Koniecpolski, later victor of the Battle of Martynov or conqueror of the Swedish king Gustav Adolf. Captured by the Turks after his defeat at Cecora in 1620, Hetman Koniecpolski did not leave Istanbul until 1623 after being bought out of captivity by Krzysztof Zbaraski's envoy. In addition to Koniecpolski, the following also ended up in Jedykuła: Mikołaj Potocki, Łukasz Żółkiewski.
However, in his chronicle, Marcin Bielski mentioned an event which proves that Polish captives could not always count on being freed. He recalled the figures of Dymitr Wiśniowiecki, a duke, and Jan Piasecki, a nobleman from Podolia, who were ordered by Sultan Suleiman the Magnificent to be put to death by hanging by a rib on a hook.

It is also worth mentioning another famous Polish prisoner - Samuel Korecki - a participant in the Battle of Klushino, who later delivered supplies to Polish troops stationed in the Moscow Kremlin. This intrepid borderland knight, captured and taken to Istanbul, was, on the orders of the Sultan, murdered before the arrival of the Polish envoy sent to make peace and exchange prisoners.

Hundreds of years later, when the Commonwealth was no longer on the maps of Europe, Polish travellers began to arrive in Istanbul and often visited the former prison. Among them was Aleksander Lesser, who commemorated his impressions with a drawing of the fortress, now in the collection of the National Museum in Warsaw. Archbishop Ignacy Hołowinski, who visited the fortress during his stay in Istanbul on his way to the Holy Land, was also in Jedykule. Zygmunt Gloger also wrote about Jedykule. In the Encyclopaedia of Old Poland, he stated that: "There was hardly a noble family in the Polish nation whose closer or further relatives captured into slavery did not undergo the execution of Jedykuł, stained with the martyr's blood of the Wiśniowiecki and Korecki families".