From the compilation of lists of the separate years it was but a step to the classification of the reigns of the kings themselves and their arrangement in the form of dynasties. Among the mass of tablets recovered from Niffer has been found a fragment of one of these early dynastic tablets,[3] which supplements the date-lists and is of the greatest value for settling the chronology of the later period. The reverse of the tablet gives complete lists of the names of the kings who formed the Dynasties of Ur and Isin, together with notes as to the length of their respective reigns, and it further states that the Dynasty of Isin directly succeeded that of Ur. This document fixes once for all the length of the period to which it refers, and it is much to be regretted that so little of the text has been recovered. Our information is at present confined to what is legible on part of one column of the tablet. But the text in its complete form must have contained no less than six columns of writing, and it probably gave a list of various dynasties which ruled in Babylonia from the very earliest times down to the date of its compilation, though many of the dynasties enumerated were doubtless contemporaneous. It was on the base of such documents as this dynastic list that the famous dynastic tablet was compiled for the library of Ashurbani-pal at Nineveh, and the existence of such lengthy dynastic records must have contributed to the exaggerated estimate for the beginnings of Babylonian history which have come down to us from the work of Berossus.