An extensive conservation work took place in the 2000s by the Aga Khan Trust for Culture, in collaboration with Aleppo Archeological Society.

The recently discovered temple of the ancient storm-god Hadad dates use of the hill to the middle of the 3rd millennium BC, as referenced in cuneiform texts from Ebla and Mari.

[9] After Aleppo was conquered by the armies of Alexander the Great, the area was ruled by Seleucus I Nicator, who undertook the revival of the city under the name Beroia.

During the clashes with the Sassanian king Khosrow II in the 7th century, the population of Aleppo is said to have taken refuge in the Citadel because the city wall was in a deplorable state.

Little is known about the citadel in the period of early Christianity and Islam, except that Aleppo was a frontier town on the edges of the Byzantine, Ummayad and Abbasid empires.

[9] Sayf al-Dawla, a Hamdanid prince, conquered the city in 944, and it subsequently rose to a political and economic renaissance.

[9][12] The Hamdanids built a reputedly splendid palace on the banks of the river, but moved to the Citadel after Byzantine troops sacked the city in 962.

Arab sources report that he also made several other improvements, such as a high, brick-walled entrance ramp, a palace, and a racecourse likely covered with grass.

Sultan Ghazi strengthened the walls, smoothed the surface of the outcrop and covered sections of the slope at the entrance area with stone cladding.

The depth of the moat was increased, connected with water canals and spanned by a tall bridge-cum-viaduct, which today still serves as the entrance into the Citadel.

During the first decade of the 13th century, the citadel evolved into a palatial city that included functions ranging from residential (palaces and baths), religious (mosque and shrines), military installations (arsenal, training ground, defence towers and the entrance block) and supporting elements (water cisterns and granaries).

[13] In 1415, the Mamluk governor of Aleppo, prince Sayf al-Din, was authorized to rebuild the citadel, which by then stood at the centre of a significant trading city of between 50,000–100,000 inhabitants.

The final Mamluk sultan, al-Ashraf Qansuh al-Ghawri, replaced the flat ceiling of the Throne Hall with nine domes.

In 1679, the French consul d’Arvieux reports 1,400 people there, 350 of whom were Janissaries, the elite military corps in the service of the Ottoman Empire.

[23] Also other phases of the citadel's restoration have been revealed, including the entrance, the minaret of Great Ayyubid Mosque, and the façade of Throne Hall.

Notable sites include: The enormous stone bridge constructed by Sultan Ghazi over the moat led to an imposing bent entrance complex.

Would-be assailants to the castle would have to take over six turns up a vaulted entrance ramp, over which were machicolations for pouring hot liquids on attackers from the mezzanine above.

[25] Ghazi's "palace of glory" burned down on his wedding night and he escaped with the queen, but it was later rebuilt and today stands as one of the most important and impressive monuments in the citadel crown.

Today, numerous architectural details remain from the Ayyubid period, including an entrance portal with muqarnas, or honeycomb vaulting, and a courtyard on the four-iwan layout, with tiling.