Halep şehri, Suriye'nin kuzeyinde, kuzeyden güneye ve doğudan batıya giden yolların kesiştiği, son derece stratejik bir mevkide bulunmaktadır. Bu özelliği ile tarihin her döneminde önemini koruyan bir kent olan Halep, 1086 yılında Büyük Selçuklu hükümdarı Melikşâh devrinde Selçuklu hâkimiyetine girdi. Selçuklu hâkimiyeti Halep'e Türkİslâm kültürünü her yönüyle yerleştirdi. Kadîm bir geçmişe sahip olan Halep'te en göze çarpan yapı, Halep Kalesi'dir. Tarihi M.Ö. 3000'li yıllara dayanan kale, Orta Doğu'da, hatta dünyada askerî mimarinin en dikkat çekici ve eski eserlerinden biridir. Eski şehrin merkezinden görkemli bir şekilde yükselir. Öyle ki uzun süre İslâm dünyasının harikalarından biri kabul edilmiştir. Halep Kalesi yapay bir şekilde oluşturulmuş eğimi ile oval biçimli doğal bir höyüğün üzerine konumlanmıştır. Düzenli bir plana sahip bulunmamaktadır. Arazisi düz olduğundan şehrin etrafı hendek, dış ve iç sur şeklinde üçlü savunma sistemiyle donatılmıştır. Selçuklu döneminde surlar elden geçirilerek tahkim edilmiş, yıkılan kısımları birçok kez onarılmıştır. Kalenin onarımı, yeni idarî ve sosyal yapıların ve savunma yapılarının inşâsı noktasında Nûreddîn Zengî'nin kale tarihinde ayrıcalıklı bir yeri bulunmaktadır. Makalemizde bir Selçuklu kalesi olan Halep kalesi ve savunma yapıları, tarihî veriler ışığında değerlendirilmeye çalışılacaktır

The city of Aleppo is located in a very strategic position in the north of Syria, where the transit roads cross from north to south and east to west. Aleppo is a city that preserved its importance in every period of history with this feature. In 1086, The Seljuks started to rule over the city during the reign of the Great Seljuk's ruler Malik-Shah. Seljuk domination indwelled the Turkish-Islamic civilization in every aspects in Aleppo. The citadel of Aleppo is the most spectacular building in Aleppo, which has a ancient history. The castle which dates back BC. 3000, it is one of the most remarkable and ancient works of military architecture in the Middle East, even in the world. It rises stately from the center of the old city. It has long been regarded as one of the wonders of the Islamic world. The citadel of Aleppo is situated on a natural oval-shaped mound with an artificially formed slope.It does not have a regular plan. Since its terrain is flat, the city is equipped with a triple defense system in the form of moat, outer and inner walls. During the Seljuk period, the city walls were rebuilt and the fortifications were repaired many times. Nur ad-Din Zangi has a privileged place in the castle history at the point of repair of the fortress, the construction of new administrative and social structures and defenses. The citadel of Aleppo, a Seljuk fortress, and its defense structures will be tried to evaluated in light of historical data in our article The city of Aleppo has been one of the most important political, cultural and commercial centers of the Middle East since its establishment. Due to Aleppo's strategic location in the north of Syria, where the transit roads cross from Anatolia to Mesopotamia and the Mediterranean to Iran, the states that wanted to dominate the region constantly desired to seize it. The Seljuk presence in the city began from the time of Tughril Beg (the first half of the XI century). Aleppo became a Turkish region in a short time thanks to Hanoglu Harun, Afsin and Sunduk Begs' raids and the intensive settlement of the Turkmens. When Sultan Alp Arslan led a campaign against Fatimid Egypt, he surrounded Aleppo and then the city had to declare its loyalty to the Seljuks. After Alp Arslan, Malik-Shah was crowned as the new sultan of the empire, he appointed his brother Tutus to the Syrian region. The primary goal of Tutus was to capture Aleppo. He made great efforts for it and eventually reached his goal in 1094. After the death of Tutush, his son Fakhr al-Mulk Radwan took over the administration in Aleppo. Duqaq, the other son of Tutush, went to Damascus and set up his administration there, then Syrian Seljuk State was divided into two parts as Aleppo Seljuks and Damascus Seljuks. The main characteristic of this period is the struggles with the Crusaders. The Syrian Seljuks were unsuccessful in the wars against the Crusaders. Along with the loss of land, very severe conditional treaties were signed.Artuqid ruler of Mardin Ilghazi succoured the city which was surrounded by the Crusaders. After Ilghazi set up his domination in the city, Aleppo Seljuks collopsed (1117). Ilghazi achieved great success against the rasing Crusades. After Ilghazi’s death, the governor of Mosul Aq Sungur al-Porsuki, took the city, but his sovereignty took a short time (1222). With the death of Aq Sungur in 1126, confusion began in the city. It is very important for the history of the Aleppo that Imad ad-Din Zangi, the son of Qasim ad-Dawla Aq Sungur, was appointed to manage Aleppo by the Seljuk Sultan Mahmud. Imad ad-Din Zangi thought the city was a center of resistance against the Crusaders, so he built it in this direction. He has achieved great success against the Crusaders, who were keeping Aleppo under pressure. As well as growing up his domination area, he also captured most of the cities and castles of Crusaders. After the death of Imad ad-Din Zangi (1146) his son, Nur ad-Din Zangi, became the new ruler of Aleppo. He proved his power with the successes and struggles with the Crusaders. He has also a special interest in Aleppo. He made many attempts to develop the city. During his reign, Aleppo lived the golden age as one of the three important cities of the Islamic world. His death in 1174 destroyed the peaceful atmosphere in the city, and for a while the turmoil prevailed. Capturing of Aleppo in 1183 by Salahaddin Ayyub, the Zangi period in the city was over. However, the development and growth of the city continued in this period without slowing down. The city walls of Aleppo were generally from the Roman period. Firstly, the walls were built in 300s B.C. The city walls, which were often repaired before the Seljuk rule, were also renovated during Aq Sungur and Imad ad-Din Zangi periods. In the period of Nur ad-Din (1157), the city walls suffered great damage in a severe earthquake. As security weakness emerged in the city, a low wall called "fasl" was built between the city and the city walls as a interlocutory injunction. the city was fortified with a second wall by the fasl that was surrounded by seven gates. With the construction of the fasl, the city walls were repaired. There is no definite information on the number of doors in Aleppo where the city entrance and exit are made. In this regard, the sources give different gate numbers. In the pre-Seljuk period (late Xth century), Makdisi, is the important geographers of the Middle Ages, came to Aleppo, records eight gates' names. Nasir-i Husrev who visited the city in the first half of the XIth century states four gates of the city. Even though Yakut al-Hamavi, who came in the first half of the XIIIth century, expresses the six gates of Aleppo, does not mention the gates' names. The citadel of Aleppo has a very ancient history like Aleppo. After the Assyrian and Hittite periods, the citadel was renewed during the Seleucid period. The castle and city walls, which were in a very bad situation during the Muslim conquest in the VIIth century, have always been repaired and by Muslim administrators. Hamdanid leader Seyfuddevle who were aware of Aleppo and its citadel's strategic importance of the defence of the region, made it capital city in 944. After that the city had one of the most brilliant periods. Seyfuddevle renewed the citadel after the Byzantine attack on Aleppo in 962. After the following Byzantine, Fatimid, Mirdas dominance, the castle preserved its importance during the Seljuk period. Especially Nur ad-Din Mahmud Zangi was interested in the castle as like the city. Due to the keep of Aleppo citadel's location and architectural characteristics it has a very difficult structure to be seized. It is considered one of the most striking and ancient works of medieval Islamic military archirecture. The citadel which is in a predominant position in the city, according to some experts its height is 40 m some 50 m with an artificially formed slope that lies on a partially natural, partially artifical oval-shaped hill. The castle was first built as a Neo-Hittite acropolis and later turned into a military fortress due to its strategic location. The sloping surface of the hill is covered with stone and the castle is surrounded by a deep ditch. The depth of the ditch is between 22 m-30 m. One of the most striking features of the castle was the entrance bridge and the monumental entrance gate. The castle did not have a proper plan. The keep of castle had the administrative office other than its military function. The palace of the ruler or city governor was here. The high-ranking of senior officials' residences were gathered around the palace. The keep of castle was repaired very frequently because of internal damage and great damage from the earthquake in the Seljuk domination. Two major earthquakes in Aleppo in 1139 and 1157 affected the castle of Aleppo negatively. In 1168, Nur ad-Din Zangi repaired the city walls with the keep of citadel in 1168. The citadel's walls were repaired, and some towers were added to it. The ditch was strengthened as it was one of the main elements of the defence, it played an important role in the struggle against the Crusaders, and was a very important subject during the reigns of Imad ad-Din Zangi and Nur ad-Din Zangi. Because the walls were damaged in the earthquake of 1170, the bastions on the west side were repaired by Nur ad-Din Zangi. He also built the "Dârü'z-Zeheb" (Golden Palace) and running path called "Green Hipodrum" on the bases of the old palace in the castle. He built new official buildings and baths beside the Golden Palace. Ibrahim Mosque, which was accepted as sacred by the Muslims called "Makâm-ı İbrâhim", was repaired. Nur ad-Din Zangi built a wooden carve mihrab and Hanafî madrasah. The sacred relics believed to belong to the Prophet Yahya were also put here. Sheikh Maruf Mosque was built during the reign of Nur ad-Din Zangi (1169). The son of Nur ad-Din al-Malik al-Salih Ismail, as he had repaired Ibrahim Mosque, also made all the doors of the inner house beautiful. As a result; due to the strategic location of the citadel, since it’s been founded, it became the centre of interest for whoever wanted to seize the area. Because seizing the citadel was equivalent to dominating northern Syria and up to Mesopotamia. The fact that it was built on a partially natural, partially artificial hill that has a steep slope and stony structure gave it a great defense advantage during the Seljuk period. Because the city was under constant threat in the north and west by County of Edessa and Principality of Antioch, it has been given great importance to walls. The steep walls, which are very difficult to overcome, have been fortified more strictly. Other elements that made it easier to defend the castle were well-tuned arrow gaps and deep ditches all around the castle filled with water which was a defensive barrie against the attackers. Due to having rich water resources there was no fear of dyıng from lack of water whenever it was under siege. The Citadel of Aleppo has remained a Turkish-Islamic fortress during the Seljuk period thanks to all these defense advantages, and played a great role in the struggle with the Crusaders. The building, which survived until recently, entered the UNESCO World Heritage List in 1986. It was renovated in 2000 with Aga Khan Trust for Culture and extensive restoration work by Aleppo Archeological Society. But unfortunately, this deeply rooted structure, like other historical works, has taken its share from the Syrian civil war. In the year of July 2015, after the exploitation of the tunnels opened unter the citadel by the Assad forces, it was severely damaged and the wall in the southeast part of the citadel was demolished