After discovering in mid-January a major "wiring error" on Plate 12 of the Great Stemma that affects every extant copy of the diagram, I am now closer to understanding how this mess-up happened.
The Great Stemma appears to be a "family tree" of Christ which was compiled in late antiquity. In its section on the Judaean kings period, it includes the names of the kings' mothers. But as has already been noticed, many of the names are not those which are carefully set out in the Second Book of Kings in the Bible. A little study shows that most of the mysterious names of wives, which seem to have come out of nowhere, can in fact be found in one of the chronicles of antiquity, the
Liber Genealogus, which uses slightly unfamiliar forms of the biblical names. This part of the analysis shows that a large block of names was simply shifted rightwards across the Great Stemma page to a new position. At least four wives' names were then shifted upwards to fill the gaps on the page. But what is most interesting of all is that the name of Queen Athalia, a bloodthirsty lady said to have out-heroded Herod by slaughtering children, appears twice on Plate 12.
I have made a graphic showing these corruptions
here (click).
Mistakes like this are a godsend in manuscript detective work. This error offers us additional proof that there must have been a timeline originally running alongside the great stemma at mid-page height. This matters, because it reveals that the Great Stemma is not just a genealogy, but a graphic version of the universal chronicles which attempted in antiquity to cross reference the histories of different civilizations to establish an overview of Middle Eastern and Graeco-Roman history.
All this, in its turn, helps us to reconstruct how the Great Stemma looked when it was originally drawn, and indirectly proves (a) that stemma design in late antiquity was much more sophisticated than medieval copies show and (b) that the lack of proper stemma alignment in all 21 known copies of the Great Stemma is almost certainly a defect in the copying, not in the original design.