This term, which means “high gate” and "sublime gate ”, refers to the Grand Vizier's mansion. As the meaning of the term expanded, the Grand Vizier's mansion became to be known as “Pasha Gate” and “Bâb-ı Âsafi”. However, the building that was re-built after the Alemdar incident in 1808 was started to be referred to as Bâb-ı Adl or Bâb-ı Adli in honor of Mahmud II, also known as Mahmud-i Adli, and, in the second half of the 19th century, the term Bâb-ı ali came back.
Initially, state affairs were discussed at Divan-ı Hümâyun (imperial council), which corresponds to the modern day council of ministers and convenes four days a week. A session used to be held at Grand Vizier's mansion under the name of “ikindi divanı" (afternoon council).
Along with the changes in the functioning of the Ottoman Empire which were introduced in the last two hundred years and the afternoon councils of the Grand Vizier taking over affairs of the state, a new meeting order was established. Clerks, books and registers that used to be pat of Divân-ı hümayun were, now, part of Bâb-ı âli. Reisülküttab (chief of officials tasked with correspondences and foreign affairs in the Ottoman Empire) and council clerks, çavuşbaşı (an official tasked with accompanying ambassadors when they'll see the sultan) and his department and attendants, master of ceremonies moved to Bâb-ı âli. These officials were called “Hademe-i Bâb-ı âli” along with kethüda (chamberlain) and mektupçu (letter officer), attendants of the grand vizier.
They played a role in the structuring of the Bâb- ı âli in the assemblies that were introduced with Tanzimat (an era of reforms in the Ottoman Empire). Meclis-i Vâla-yı Ahkâm-ı Adliye and Dar-ı Şûra-yı Bâb-ı âli that were established in 1838 brought a new dimension to the Ottoman bureaucracy.
There was no other place other than Cağaloğlu in order for Grand Vizier mansions to be located nearby the palace. Although Naima (first Ottoman chronicler) points out in his history that Kemankeş Kara Mustafa Efendi, who was the grand vizier during the reign of Sultan Ibrahim I, had a palace in the palace of the present day Bâb-ı ali and that officers were also present there, official opening of the place as Bâb-ı ali was done by Sultan Osman III in 1756. Thus, it became the head building which permanently housed the Grand Vizier's mansions and where the state affairs were actually managed. After the fire in 1839, it was no longer residence of the Grand Vizier and it fully gained a government department status from 1844 onwards.
Bâb-ı âli was on fire for six times. There is a another meaning that should be derived from such fires apart from fires that affected the entire Istanbul and wooden structure of buildings. Since the janissaries held the grand vizier responsible for the deterioration of the order, they gathered around the mansion and set it on fire. Location of the Grand Vizier's mansion became the starting place of the fire.
These structures which have been burned and renewed many times have survived to the present day with horizontal structures with the simple imperial facades by Stefan Kalfa. Bâb-ı âli gate with baroque eaves and cover, in the form of a triumphal arc with a fountain, across from the two-storey Regiment Mansion that represents the power of the Palace, reflects the the symbolic expression of execution that focuses on the grand vizier and the government and also carries hierarchy to the architecture since it is lower than the Regiment Mansion. Bâb-ı alı is the first public building in the Ottoman Empire.
This new Bâb-ı alı, built by Stefan Kalfa, is also distinguished from former ones, except for floor coverings, in that it is masonry. Although various changes and demolitions took place on it, the main lines created by the architect still remain unchanged. However, the old space layout was only preserved on the side of the former Sadaret Dairesi (Grand Vizier's Office), which is now used as the provincial mansion. The original structure consisted of rooms lined around large halls connected to each other in the northwest-southeast direction. These long sections with a length of about 220 meters were low at the end, yet there was a high section in the center. The said low sections were Sadaret office in the northwest, the Hariciye Nezareti (Ministry of Foreign Affairs) office in the southeast, and Şura-yı Devlet (Ottoman Council of State) office between the two.
Although it differs from the former Bâb-ı ali in terms of architecture, it is seen that the main principles that create the new administration center are largely connected with the old approach. For example, since the classical period, the central financial administration and civilian administration of the state had always been autonomous from each other, but these two administrations had created two large bureaucratic masses within themselves. Such formation also proves that the principle of separation of powers had been kept alive for ages.
The location of the new Bâb-ı âli, built in 1844, changed along with its function. From this date onwards when Topkapı Palace lost its importance and remained only as the approval authority, the gate overlooking the Regiment Mansion lost its function and the southern gate overlooking Ankara avenue which houses Hariciye (Ministry of External Affairs) became important. Because, now, the name of the government which manages affairs of the Ottoman Empire is Bâb-ı âli. With the increasing importance of Hariciye (Ministry of Foreign Affairs), journalists who are close to the news started to settle in this neighborhood and the phrase Bâb-ı âli which meant the Turkish press for many years came into being.
In the following years, two other important structures were built within the Bâb-ı âli area apart from the main structure in question. The first is the archive building used by Hazine-i Evrak Nezareti (Ottoman Archive) which was designed and built by Swiss-Italian architect Gaspare Fossati. The building by Fossati attracts attention with masonry walls, floor coverings, stairs, door and window wings made of iron which were produced at İstanbul Shipyard and with its Terazzo design that is rarely encountered in Turkey.
The second building at the Bâb-ı âli is a small building, also used by the archive, which was built on the side of Ankara avenue in 1910 and built in line with the First National Architecture Movement. The main Bâb-ı âli structure suffered from two more big fires after it was built in 1844. In the first fire, a portion of the section housing the Şura-yı Devlet and the southeastern part burned and damages parts were quickly restored. In the second fire in 1911, the middle section burned again, and it was not restored again and abolished. Thus, two separate structures emerged, not a single mass. The fact that structures divided into two masses ruined its architecture which was expression of the bureaucratic organization of Bâb-ı âli and constituted a vivid, yet singular massive and functional whole which is similar to Dolmabahçe palace.
Starting from declaration of the Republic, the former Sadaret office was used as the Provincial Mansion, and the neoclassical decorations on the building were removed and it was plastered plainly. The Provincial Mansion underwent a series of restorations in the late 1980s and 1997 to restore the structure to its original appearance.