The Hashishin, started under Hassan-i Sabbah in the mountain fastness of Alamut, are typically used as bad guys in stories. But for much of his life, Hassan-i Sabbah was considered a hero of great renown. His "assassins" were the ninja of the Middle East when the Crusades came rolling in to town. There was actually once talk of the Hashinshin converting to Christianity and forming an alliance with those same Crusaders, but then something or other happened and they went back to being an independent force in the area (actually making two attempts against Saladin as well as the crusaders and other important rulers in the area). I don't know if anyone has written the story from inside the Hashishin? Not that I'd personally like to live on Alamut (or in the general area for that matter, the Hashishin we're cold blooded murders after all and by all accounts ruled their territory with an iron fist), but that must be a fascinating history and study for a character driven novel.