Of the hundreds of thousands of worshipers and sightseers who have entered the Cathedral of St.-Lazare in Autun, on a hill 150 miles southeast of Paris, probably only a handful have seen or pondered long over the words carved at the foot of a primitive Christ above one of the doors. The words are "Gislebertus Hoc Fecit," and thanks to this signature, the glories of medieval European art do not, as in almost all instances, have to be written off as the work of devoted but anonymous artisans.

In France last week, Gislebertus was enjoying a sudden spurt of fame. Just out...