For decades, parodies featuring ominous, mysterious cults have been a favorite gag in pop culture. These fraternal brothers are often depicted in some type of underground lair, dressed in extravagant ceremonial robes with their faces hidden in their hoods, seated around a long table brimming with Gothic chalices, skulls, and glittering dark treasure. Flicks on the more morbid side might even show choppy, flashing imagery of blood, torture, and sacrifices.

Like all art, creativity is sparked by a source of inspiration, and the inspiration for scenes like those have for centuries come from conspiracy theories, which often have profound impact regardless of their veracity. Indeed, conspiracy theories are nothing new: when the Great Fire of Rome occurred in 64 A.D., Suetonius and Cassius Dio, two of Nero's ancient biographers, were adamant that it was the emperor himself who set the fire (or ordered it set), and they are the originators of the myth that Nero played the lyre, danced around his palace, and sang "The Sack of Troy" while Rome burned outside his windows. Nearly 2,000 years later, people still believe the incredibly popular myth that Nero fiddled while Rome burned, even though no fiddle existed there at the time. The phrase remains a staple of English lexicon, and what's often overlooked is how the actual fire and the actual events that transpired affected history, particularly that of the persecuted Christians.

Perhaps it should also not be surprising that the themes found in contemporary conspiracy theories are often echoed in ancient conspiracy theories. While some people still insist that Lyndon B. Johnson was in on John F. Kennedy's assassination, it was speculated across the ancient world that the young Macedonian king, Alexander the Great, conspired to have his own father, Philip II of Macedon, assassinated. Likewise, the New Age beliefs that Mesoamerican ruins in Mexico were somehow tied to extraterrestrials find common cause with people who believe the ancient Indus Valley site at Mohenjo-daro was destroyed by a nuclear weapon. And through it all, the lack of surviving documentary evidence about much of antiquity has allowed for all of the unknowns to become highly speculative sources of debate. For example, did Caesar's men burn the Library of Alexandria in the 1st century B.C., or was it destroyed later, if at all? Some people even suggest that the Library of Alexandria, whose ruins have never been located, never existed at all.

Few eras are easier to let the imagination run wild than the Middle Ages, which have often been coined the Dark Ages based on a perceived lack of progress and information. In some respects, that is not completely unfounded because less is known about that historical period compared to the eras that came after it. In addition, it was a period marked by a great number of deaths caused by plague epidemics, crusades, and inquisitorial persecutions. Often, researchers are not even sure how and why certain events happened.

The era was very harsh, difficult, and often gloomy. In that greyness, burdened by various fears, people were looking for something that would light up their lives and bring them a feeling of beauty and joy. People experienced all things and events around them more intensely than people do today. They often exaggerated the events that happened, giving them a mystical and divine character. For this reason, medieval sources are taken with a grain of salt and are first carefully examined before believing.

At the same time, some historical mysteries about the era may never be solved, if only because the relevant excavated material has been lost or the archaeological site has been destroyed. In other cases, it is because new evidence is unlikely to emerge, or the surviving evidence is too vague to lead to a consensus. Of course, the lack of answers only makes these enigmas more intriguing.