Sorry New Hampshire, your craggly old man is still absent from his mountaintop perch. I'm talking, of course, about the "old man" in northern Persia, Hassan i Sabbah, who popularized the secret society movement with his devoted throng of assassins in the 11th-12th century.
Owing to my recent obsession with the Assassin class from AD&D [see most of my posts from October - November of last year], anything with the word assassin in it tends to catch my eye lately. So when I was trawling the internet for cool downloads the other day, First Edition Dungeon Module I15: The Assassins of Abu-Dala by R.C. Pinnell smacked me across the oculars like an errant tether-ball. It's a desert-based assault on a mountain fortress described as having once been "home to the old man of the mountain; better known as the father of assassins." Nice! Also, there's a bit about the assassins ransacking caravans and slaughtering them to a man, which may or may not be a reference to the dastardly modus operandi of the Cult of Thuggi in India--whence the term "thug"--which was yet another secret society devoted to murder. Anyway, I dig anything with a cool historical reference that I'm even mildly knowledgeable about so I'm taking my gang of PCs through this one next.