614 – 911 CE (297 interpolated calendar years in the Early Middle Ages)
defining boundary
10-day vs 13-day Julian equinox drift at Pope Gregory XIII's 1582 calendar reform
proponents or Body
Heribert Illig & Hans-Ulrich Niemitz (1991)
key evidence
Gregorian calendar drift calculation, scarcity of 7th–9th century archaeological strata, Romanesque-to-Carolingian continuity
Core Principles & Analysis
Formulated in 1991 by German historian Heribert Illig and Hans-Ulrich Niemitz, the Phantom Time Hypothesis examines the 1582 Gregorian calendar reform of Pope Gregory XIII, which corrected the Julian calendar (instituted by Julius Caesar in 45 BCE) by dropping 10 days instead of the ~13 days of astronomical drift required for 1,627 elapsed years.
Because each century of the Julian calendar accumulates roughly 0.78 days of equinox error, a 10-day discrepancy corresponds to approximately 1,280 years rather than 1,627 years, leading Illig to conclude that 297 years (AD 614–911) never elapsed.
Illig proposes that Holy Roman Emperor Otto III, Pope Sylvester II, and Byzantine Emperor Constantine VII revised the calendar around the year 1000 CE so that Otto's reign would coincide with the millennial year of the Christian era, fabricating or retrojecting the Carolingian dynasty and Charlemagne into the resulting three-century gap.