- "I am no traitor... for I cannot betray those I never truly loved."
- ―Haras to Altaïr regarding his betrayal of the Assassins, 1189.[src]
In 1189, Haras betrayed the Assassin Order, and led an army of Templars to attack the Assassins' fortress of Masyaf. During the assault many Assassins were killed, and their Mentor, Al Mualim, was captured. Arriving back at Masyaf, the Assassin Altaïr Ibn-La'Ahad fought his way through the village and confronted Haras, who then threatened Altaïr with the death of Al Mualim.
Promptly retreating to the now Templar-occupied fortress, Haras proceeded to execute a number of Assassin hostages with his crossbow. Altaïr, who was locked outside the fortress by a portcullis gate, promptly scaled its walls and assassinated Haras.
As he died, Haras continued to defy the Assassins, claiming that the Templars knew the truth about humanity and that the Assassin's Creed was wrong. Soon after, Haras passed away, his beliefs unchanged despite Altaïr's words.
Personality and characteristics
- "You put too much faith to the hearts of men Altaïr. The Templars know the truth. Humans are weak base and petty."
- ―Haras to Altaïr, 1189[src]
According to Altaïr's suspicions, Haras was a man who sought the easy route instead of rightfully earning his place. He also had a reputation for being chameleon-like in combat, and could adapt his personality to suit others in order to find out their secrets.
Haras has an unquestionable loyalty to the Templar Order, saying that they know the truth about humanity and was willing to murder Al Mualim for his master if he could not get the answers for the 'artifact' he seeks. Due to his loyalty to the Templar Order, he was not above executing his former brothers. 
However, his ambitions could take over him at times, leading to him hastily taking the opportunity to join the forces of the Crusaders, donning their uniform as he betrayed his fellow Assassin brothers.
- Haras's armor bore the emblem of the Kingdom of Jerusalem. Though a Templar, its color scheme was that of the Knights Hospitalier.
- Even though Altair assassinates Haras with the Hidden Blade, he is shown sheathing his sword as the scene cuts into the memory corridor. In the novel, Altair did kill Haras with a sword.
- It is unknown if the master mentioned by Haras is Grand Master Gerard de Ridefort or Basilisk since the former dies in October 1189, and it is not specified what month in 1189 the Siege of Masyaf occurs.