Alep is one of the largest cities in Syria. During the Third Crusade, it was the location of an Assassin fortress which served as the primary base of operations for the Levantine Assassins in 1190. There, the Assassin Altaïr Ibn-La'Ahad assassinated Harash, the second-in-command of the Assassins for betraying the Brotherhood.
The Citadel of Alep was one of many castles that the Assassins used as their headquarters during the Third Crusade. The city was under the control of the Ayyubid Sultanate, but the Saracens and Assassins tolerated one another's presence and cooperated in the city. In 1190, it even served as the main base for Al Mualim and his lieutenant Harash.
As a result, Altaïr Ibn-La'Ahad operated primarily from this city that year. It was while returning to it after having completed one of his missions that he found the outskirts of the city attacked by Crusaders. The Crusaders were keen on locating the legendary relic called the Chalice, and had pursued an Assassin agent to a village just outside Alep for information. After retrieving this information from the Assassin, whom they killed, they proceeded to massacre the entire village and raze it to the ground.
Altaïr ultimately managed to assassinate the commanding officer of this Crusader detachment, and he and the survivors were able to alert the nearby Assassin citadel, which mounted a counter-attack shortly afterwards. As soon as he returned, Altaïr was briefed on his new assignment: to recover the Chalice lest it should fall into the hands of the Crusaders or Saracens.
When he returned later that year, Altaïr did so covertly, rather than as an ally. He had managed to find the Chalice, but it had turned out to be a woman, none other than a friend he loved named Adha. Adha had informed him of the treachery of Harash, Keeper of the Assassins, who had been bribed by the Templars to serve as their spy. As a result, the Assassins under direct control by Harash were colluding with the Templars, whether they knew it or not, and the Templars themselves were able to enter to meet with Harash in secret, compromising the stronghold's security. Although Altaïr managed to cleanse the fortress, killing Harash, Al Mualim relocated to Masyaf as their main base the next year.
Later, after Altaïr's failure at Solomon's Temple, the city was recalled by an informant in Damascus, during the assassination attempt on Abu'l Nuqoud. The man asked Altaïr about Adha and mentioned their past adventures in Alep, but the Assassin quickly dissolved the conversation, not wishing to be reminded of the tragedy that had followed from that point.
- Alep is the French name of the city. In Arabic it is known as Halab, and in the English language, the name's Italian variant, Aleppo, is used.
- Unlike Masyaf and Alamut, the Assassins never historically controlled Alep, though they did have a strong presence there during the reign of Fakhr al-Mulk Radwan.
- The image of Alep from "Coming Home", the first memory sequence of Assassin's Creed: Altaïr's Chronicles shows Templar banners hanging from the walls in spite of the city being controlled by the Saracens and Assassins.