Some ten years ago, I read about Illigs thesis of surplus centuries within historical records. My first idea (I have a professional background in physics) was that it should be quite easy to disprove this funny theory: Just verify the approximate proportionality between 14C-age and backward year-count of dendrochronology and it's gone.
I had to learn that it's not that easy: W. Libby had received his Nobel Award for the conception of an independent physical method to determine the age of organic samples. Today, the approach is different. 14C age has to be calibrated against dendrochronology using the IntCal04 dataset. Radiocarbon measurement simply marks the positon on a dendro scale.
The user has to believe that this scale is free of errors, as its tree-ring patterns were never published! When I asked the director of the dendro departement at the University of Hohenheim, he confirmed this situation, unique throughout science.
Since then, I have investigated dozends of data-sets, but I'm still looking for a hint that the records of history are correct and, for example, Clovis the great has lived some 1500 years ago...
- more info on http://www.jahr1000wen.de/year1000.html