In 1986 (or was it year 1689?), Illig began developing the Phantom Time Hypothesis. This idea states that years 614-911 A.D. never happened. Apparently, the suspiciously skimpy collection of documents from this time period raised an eyebrow for Illig, so he got to thinking. Maybe, he thought, the early Middle Ages were completely fabricated. Illig and other Phantom Timers hold that important historical figures said to have been alive at this time (Charlemagne and Alfred the Great, for example) either existed at different points in time, or were totally fictional. Illig believed that the legacy of Charlemagne, specifically, was too extraordinary to have been possible. Easy enough.
This huge leap in history's timeline may have been a result of some confusion when the Pope switched from the Julian calendar to the Gregorian calendar in 1582 A.D., where there was a discrepancy of at least 10 days. Maybe there was a misinterpretation of documents somewhere along the line, as forged historical documents aren't necessarily rare. But maybe it was no accident at all. (Cue the dramatic gasps.)