Assassination of Genghis Khan

"I had planned to infiltrate the Mongolian camp with Qulan Gal. It was said that Khan was there, too."

- Altaïr, reporting on the assassination.

The Assassination of Genghis Khan was an event during the High Middle Ages in which Darim Ibn-La'Ahad, with the help of his family and the Assassin Qulan Gal, brought down and killed Genghis Khan.

Before the assassination
Preparing for his trip to the East, Altaïr left the leadership of the Assassin Order in the hands of Malik, supported by Sef to fend off any affairs. Then he took Maria Ibn-La'Ahad and his son Darim Ibn-La'Ahad, and left Masyaf, travelling through Persia, India and Mongolia, to eventually the Mongolian camp in the Xia province.

Altaïr thought that Genghis Khan possessed a Piece of Eden, similar to the Apple or perhaps the Sword, which he used to power up his unstoppable Mongolian march.

Source

 * Assassin's Creed: The Secret Crusade