The Phantom Time hypothesis is the theory that the Dark Ages, the period in Europe immediately after the collapse of the Roman Empire, did not in fact occur. It is stated that the 'missing' years are a result of the change from the Julian to the current Gregorian calendar, made worse by medieval reliance on oral history (such as the legends of Charlemagne, King Arthur and Robin Hood). Another factor is the desire of many medieval rulers to present the history of their families or kingdoms as being longer than in reality. The theory is said to explain the almost complete lack of invention and progress in Europe over a period of 500 years.
I mentioned this theory to a certain Telelelene mystic, she told me
that the years had not been misplaced, but stolen, and taken to lands
within the world of Teleleli. Her meaning, like most pronouncements by
such people, is unclear to me, and I present her words to the reader
without judgement as to their value.