Isaac Comnenus

Isaac Comnenus or Isaac Komnenos, was the ruler of Cyprus before King Richard had defeated him. After his fall, he was imprisoned by the Templars, who bought Cyprus for their own needs, effectively making the island their major base. He was later executed by Armand Bouchart before the events of Assassin's Creed: Bloodlines.

When Altair confronted Armand Bouchart in Templar Archive, he reveals that Isaac Comnenus was, in fact, a Templar himself. He was the keeper of the Archive. However, he was a foolish man, and make an enemy in King Richard. The Templars had no options but to buy the island, punish Isaac (and kill him), and evacuate the Archive.