Ever since its establishment, or more accurately since the capital city was transferred from Rome in 330, Constantinople has always attracted attention, whether it belonged to Roman-Byzantine or Ottoman civilization. Upon its conquest by Mehmed II el-Fatih in 1453 Constantinople became Istanbul, the most significant center of Islam, “studded” with many buildings, particularly mosques. Relying both on Byzantine heritage and new Ottoman achievements, as a political and civilizational center, Istanbul began to attract people from all parts of the Empire, settlers from Anatolia who pursued better life, Bosniaks from the Balkans who sought recognition, Jewish refugees from Spain, Greek converts loyal to the new empire, Venetian merchants seeking markets, religious scholars attracted by famous madrasas and many others.

Today, we are quite familiar with the appearance of Istanbul in its early period. The term ‘early period’ can be defined in two ways: the period before 1500, which besides the practical date matches significant changes in Ottoman architecture, and the period before 1539 when Mimar Sinan as the main architect of the Empire appeared. Besides buildings and a large number of historical documents, we now have several other sources which provide information on Istanbul of the time. It is particularly interesting to refer to a work of art which, better than any other travelogue, visualizes the well-known buildings which existed in about 1539. It is a miniature by Nasuh Matrakčija entitled “A View of Istanbul and Galata” from 1537, which was part of the extensive work “Fetihname-i Karabuğdan”.

Matrakčija was the founder of landscape miniature and one of the greatest artists in the history of the Ottoman Empire. His approach to such pictures was documentary and taxonomical since he tried to present both the artistic and the actual image of the city, which would not be subjected to imagination or cliche. Therefore, it is easy to recognize individual buildings in his miniatures, accurately positioned at their historical locations. “A View of Istanbul and Galata” is the most famous representation of Istanbul of the early period, before the construction of buildings by Mimar Sinan. Before 1537, four sultans ruled Istanbul: Mehmed II el-Fatih (1451-1481), Bayezid II (1481-1512), Selim I (1512-1520) i Suleiman I Qanuni (1520-1566). All of them had their main sultan mosques built in Istanbul, though Sultan Suleiman Mosque was built only in 1557.

With respect to building during Sultan Mehmed, one should particularly single out three mosques the founders of which were his viziers (and which can also be seen in Matrakčija's miniature). Mahmud Pasha Mosque was built in 1462-1463 (in the same year when building of Sultan Fatih Mosque began) and has the features of the Bursa style with two longitudinally positioned domes of the same size. Murat Pasha Mosque was also built in the Bursa style. It is situated in the present Aksaray district. The mosque follows the pattern of the Mahmud Pasha Mosque, with two identical domes covering the praying space. Soon after its building, mosques with a central dome and a completely new concept of space began to prevail. The Rum Mehmed Pasha Mosque, built in 1471, is an early design of the kind. The design of this mosque would serve as a litmus paper for future ones, which would include smaller domes on the sides and a semi-dome in the front (inverted T design), which was a promising and potential leitmotif of the early Istanbul architecture of middle-size buildings. Ultimately, there were not a lot of them, and they would receive its pure expression in the design of Gazi Husrev-beg Mosque.

The early Istanbul style refers to a turning point in Ottoman architecture and the emergence of mosques with the dominant central dome and a more pronounced vertical structure. The name refers to the new capital of Ottomans, since it is there where it became completely apparent. What we are interested in here is the inverted T design, which we can observe in three mosques of the early Istanbul style, which chronologically influenced each other: Rum Mehmed Pasha Mosque (1471), Atik Ali Pasha Mosque (1496-1497) and Gazi Husrev-beg Mosque (1531). All the three have the central dome with a semi-dome toward the mihrab and small domes on the sides.

Gazi Husrev-beg Mosque is the last big project of the early Istanbul school and we see it as a follower of what had already been offered in Rum Mehmed Pasha and Atik Ali Pasha mosques. In literature, it was previously associated with the latter; however, if we want to be consistent, we should highlight Rum Mehmed Pasha Mosque as an important first link of the chain, since it is there that we first observe the system of semi-dome in the front and tetime (structures adjoining the mosque) on the sides. Later on, Atik Ali Pasha Mosque went a step further, since double tetime, without walls, are fully merged with the central space. Gazi Husrev-beg Mosque refers to the other two, though it has a new concept, i.e. one tetima on each side which is fully merged with the central space. In this case we observe a pure inverted T design, which could also have some traps, in the sense that side tetime are suppressed parts of the mosque which do not have clear communication with the main praying space. This problem is observed when you enter the Gazi Husrev-beg Mosque and it is not negligible. Ultimately, it was only partially solved and, unlike Atik Ali Pasha Mosque, tetime are here really experienced as separate parts of the mosque. Nevertheless, the interior of the mosque leaves the impression of spaciousness and solemnity, due to the extremely high dome (24 meters) and luxuriant stone sculptures. It reveals a high style of building compatible with the best Istanbul creations.

During its building, Gazi Husrev-beg Mosque exceeded logistic capacities and civilizational frameworks of Sarajevo of the time, as a city which only began to develop. We will not exaggerate if we say that Sarajevo can be described as a city before and after building of the mosque, i.e. the time before and after the appearance of Gazi Husrev-beg at the historical stage. It was then that Sarajevo became a big city and a significant cultural and economic center. Gazi Husrev-beg Mosque was built in 1531 (final works), by architect Adžem Esir Ali. It is interesting to note that no other bigger or more significant mosque was built in the Ottoman Empire over the following twenty years, which confirms its importance. Besides, it was the last big design of early Istanbul architecture. If it had been built in Istanbul at the same time, it would have been one of the biggest Istanbul mosques and remained one until the present day. More accurately, it would have been in the rank of Atik Ali Pasha, Rum Mehmed Pasha, Davut Pasha, Mahmud Pasha and Murat Pasha mosques which, besides sultan mosques, are considered as the biggest Istanbul mosques.