Born into a powerful family, Robert de Sable was immersed from birth into nobility. Though events during De Sable's life are difficult to pin down, at some point he became lord and ruler of Briollay, France. Subsequently, Robert de Sable entered into the order of Knights Templar and reigned as their "Grand Master" in 1191. During the Third Crusade, de Sable and the Knights Templar laid siege to the city of Acre, which soon fell. Throughout August 1191, they also recaptured many fortresses and cities along the Palestinian coast, which had been lost previously.
Robert:Oui, master of lies. You and I are just two more pawns in his grand game. And now, with my death, only you remain. Do you think he'll let you live, knowing what you do?
Altaïr:I have no interest in the treasure!
Robert:Ah, but he does. The only difference between your master and I is that he did not want to share. Ironic, isn't it, that I, your greatest enemy, kept you safe from harm? But now you've taken my life... and in the process, ended your own!
Trivia
In the game, Robert was in his mid 30's when he was killed by Altaïr. In real life, he was relatively old when he died of natural causes. Robert died in the Holy Land on 23 September 1193.