Jamal was a member of the Levantine Brotherhood of Assassins, serving the order under Al Mualim in the time of the Third Crusade. He betrayed the Assassins in 1191 when the Knights Templar assaulted the Assassin base, colluding with another local, Masun, in opening the gates to the intruders.
By 1191, Jamal and a Masyaf herald, Masun, had gotten into contact with the Templar Order. They soon converted to their ideology and acted as the order's secret agents within the Assassin stronghold. For communication, the two employed the aid of a local basket weaver, who served as the medium by which they exchanged letters.
In July, their roles became especially pivotal when a Templar force under the command of Grand Master Robert de Sablé invaded Masyaf in pursuit of the Apple of Eden lost to Assassin Malik Al-Sayf at Solomon's Temple. To assist the Templars, Jamal personally sent a letter to Masun, again through the basket weaver, ordering him to open the gates for the Templars to enter the village.
Despite this critical act and the numerous casualties suffered by the Assassins, the Templars were repelled thanks to a trap triggered by the Master Assassin Altaïr Ibn-La'Ahad which collapsed giant wooden logs onto their army at the front of the fortress. After the Templars had been driven from Masyaf, Altaïr was demoted all the way to the rank of novice for the disastrous part he played at Solomon's Temple that had led to the battle in the first place. As a first step towards regaining his standing, he was ordered to seek out the Assassin traitor.
Even before Altaïr was assigned this mission, Masun's treachery had already been discovered by the other Assassins. However, they delayed their arrest as a test for Altaïr. In the meantime, Masun left coins hiding near a dead cypress tree in the village and wrote a letter to Jamal urging him to take the money and flee to Damascus where he would be contacted again once the situation had stabilized.
Jamal, however, never received this letter, as it was pickpocketed from the basket weaver by Altaïr not long after Masun handed it to him to discover the identity of Masun's accomplice. As a result, he was still at Masyaf when Masun was captured publicly preaching against Al Mualim and subsequently executed. In spite of Masun's expressed concern for Jamal's life in his life, he had revealed to Altaïr that Jamal was his accomplice when interrogated by the Assassin.
After Masun's execution, Al Mualim determined that Jamal's arrest would not fall to Altaïr, who would instead receive a different mission: to kill the nine leaders of the Templars. Despite Jamal's treachery, Al Mualim was not above the possibility of granting him amnesty if it were discovered that the traitor had been manipulated by deception or threats. However, mercy would not be granted if he had acted with intentional malice or zealous support for the Templars. As Altaïr rode out from Masyaf to Damascus to assassinate Tamir, he passed by Jamal standing at his post just outside the village in the countryside, still posing as an Assassin.
- Jamal is a transliteration of the Arabic name جمال, meaning "beauty".
- Originally, he was to be an assassination target in Assassin's Creed, but was ultimately cut from the final game due to constraints on Ubisoft. However, he still appears as a minor Easter egg.
- When in Eagle Vision, Jamal appears as the only red enemy Assassin, and if he is assassinated, the other Assassins will ignore it. If he is openly attacked however, the other Assassins react as any other guard and attack.
- Altaïr Ibn-La'Ahad's investigation of Masun and Jamal and all mentions of their betrayal are omitted from the novel Assassin's Creed: The Secret Crusade.