The first Council Hall was a wooden structure built under Fatih Sultan Mehmet II (the Conqueror) (1451-1481). The present arcaded structure is the product of the re-construction work conducted in 1527-29 under Sultan Süleyman the Magnificent by Chief Architect Alâeddin and the various successive renovations performed thereafter. The interior walls were marble coated during the 16th century. Certain ornaments and the stalactite column heads and arches of its porch and the symbol of power marble crowned empty archway dates from the 16th century period of the building. The structure received its present-day appearance through the ornaments added-on during the renovation performed in 1792 under the reign of Sultan Selim III. The archways were closed with gilded grids and doors with rococo reliefs were added-on. One of the two inscriptions in verse on the façade of the building, which underwent a further renovation in 1819 during the reign of Sultan Mahmut II, belongs to Sultan Selim III and the other to Sultan Mahmut II. The arch wall of the Clerk’s Office of the Imperial Council (Divan-i Hümâyûn) bears the monograms of Sultan Mustafa III.
The Imperial Council (Dîvan-i Hümâyûn), also called Kubbealtı, consisted of three departments, namely, the Council Chamber as such where state affairs were being discussed, the clerk offices where the decisions taken by the Council were put in writing, and the registry (Defterhane) where the documents and decision records were archived. The Imperial Council would convene four days a week. The members of the Council, namely the Grand Vizier, the Kubbealtı Viziers, the Supreme Military Judges of Anatolia and Rumelia (the European part of the Ottoman Empire) would deliberate on state affairs, take decisions and pronounce judgments on judiciary cases to be submitted to the Sultan as the highest authority. The Sheikh ul-lslam, the chief religious official in the Ottoman Empire, (Şeyhülislam) would, when invited, participate in some important meetings. Other officers of the Council were, the officer in charge of affixing the monogram of the Sultan on decrees and other official documents: nişancı; the treasurer: defterdar; the Head of the Clerks and Foreign Minister: Reis-ül Küttab; the writers of official communications/messages, permits, licenses and certificates: tezkereciler and the clerks: kâtipler. At these meetings, the state's political, administrative, financial, and customary affairs and important public cases were discussed. The Council Hall was also the venue where Grand Viziers would receive foreign ambassadors and where the wedding ceremonies of Sultan's daughters would take place.
The Ottoman Sultans would not participate in the meetings held at the Council Hall (Kubbealtı). Most of the times they would follow the deliberations of the Council in a room of the Tower of Justice from behind a grilled window overlooking the Council Chamber. When the Sultan disagreed with a particular decision of the Council, he would close the window curtain as a signal to terminate the meeting. In such case, the Grand Vizier and viziers would then proceed to the Audience Chamber in order to continue their consultations on the subject matter in the presence of the Sultan. (Miniature of a Council meeting and d'Ohsson engraving).
The Council Hall (Kubbealtı) is characterized with a series of symbols embodying the justice of the state. The fact that the interior of the Council Chamber is visible from the outside since it is separated from the exterior only through gilded grids meant that the decisions of the Council were non-confidential and of a public nature. On the other hand, the fact that the Sultan was following the Council meetings from his grilled window meant that although he had delegated his powers to the Statesmen sitting in the Council, he was personally ensuring that no injustice was committed against the citizens of the Empire.