Even more than his writing or game design, Gary Gygax is known for his imagination. The number of his unique creations—monsters and gods, spells and artifacts—that have entered the collective consciousness is truly mind-boggling. Yet like all great artists, Gary's inventions didn't spring full-formed from nothing, but rather were rooted in part in his deep love of history. For in order to create new mythology, you have to understand the existing ones.
This desire to explore and create variations of differing real-world belief systems is undoubtedly part of what led him to write Death in Delhi. While the previous Setne Inhetep books—The Anubis Murders and The Samarkand Solution—had allowed him to do great work imagining alternate versions of the ancient Egyptian pantheon, Gygax was always looking for new ground. And he found it—a whole subcontinent of it, in fact—with Death in Delhi.
One of the more interesting points of Indian history, and which plays an important role in the novel, is the concept of Thugee. While historians continue to clash on the extent of the practice, and what role the British played in expanding and disseminating the stories, the Thugs of India were part of a tribal system of organized crime centered around the worship of Kali, Goddess of Destruction. Descending in wild charges or carefully infiltrating parties over a period of weeks, gangs of Thugs would attack caravans traveling long distances and slaughter every man, woman, and child, strangling them with yellow handkerchiefs. The spoils would then go to the Thugs, who would carefully bury the bodies and remove any trace of evidence, making it seem that the caravan simply disappeared. It's from this tradition of mass slaughter and robbery, which some have estimated cost millions of lives over a period of centuries, that we get the modern English term "thug."
Of course, if there's something that sinister in our India's past, then you know Magister Setne Inhetep and his bodyguard Rachelle are bound to encounter it in Gygax's own Lands of the Peacock Throne.
For more information on Thugee, check out what Wikipedia has to say, or pick up a copy of Death in Delhi and go straight for Gary's own take on it.
Because the only thing stranger than fantasy is history.