Grand Master of the Assassin Order

The title of Grand Master was the highest rank attainable within the Order of Assassins and granted the bearer full control over their sect of the Order.[1] It was comparable to the Templar rank of the same name.
By 1191, the Grand Master of the Syrian sect was Al Mualim, who ruled from the Assassins' fortress in Masyaf, within the Kingdom of the Holy Land. The following year, after the revelation of Al Mualim's membership within the Knights Templar and subsequent death, the title was taken by his executioner Altaïr Ibn-La'Ahad, who would utilise his Piece of Eden to fashion himself an incredibly strong, yet lightweight set of "Grand Master robes".[2]
To distinct himself from Assassins and Master Assassins, Al Mualim wore a black attire instead of the default Assassin white attire. But other known Grand Masters mostly wore Assassin white unforms, though they have been seen with a black attire in their past. Ezio wore an armor with a black attire with Altaïr's armor and will at one point wear it again in Assassin's Creed Brotherhood.