In the absence of any definite synchronism, such as we already possessed for deciding the inter-relations of the early Babylonian dynasties, other means were tried in order to establish a point of contact. The capture of Nîsin by Rîm-Sin, which is recorded in date-formulæ upon tablets found at Tell Sifr and Nippur, was evidently looked upon as an event of considerable importance, since it formed an epoch for dating tablets in that district. It was thus a legitimate assumption that the capture of the city by Rîm-Sin should be regarded as having brought the Dynasty of Nîsin to an end; such an assumption certainly supplied an adequate reason for the rise of a new era in time-reckoning. Now in the date-formulæ of the First Dynasty of Babylon two captures of the city of Nîsin are commemorated, the earlier one in that for the seventeenth year of Sin-muballit, the later in the formula for Hammurabi's seventh year. Advocates have been found for deriving each of these dates from the capture of Nîsin by Rîm-Sin, and so obtaining the desired point of contact.[15] But the obvious objection to either of these views is that we should hardly expect a victory by Rîm-Sin to be commemorated in the date-formulæ of his chief rival; and certain attempts to show that Babylon was at the time the vassal of Larsa have not proved very convincing. Moreover, if we accept the earlier identification, it raises the fresh difficulty that the era of Nîsin was not disturbed by Hammurabi's conquest of that city. The rejection of both views thus leads to the same condition of uncertainty from which we started. A fresh and sounder line of research has recently been opened up. A detailed study has been undertaken of the proper names occurring on contract-tablets from Nippur, and it was remarked that some of the proper names found in documents belonging to the Nîsin and Larsa Dynasties are identical with those appearing on other Nippur tablets belonging to the First Dynasty of Babylon.[16] That they were borne by the same individuals is in many eases quite certain from the fact that the names of their fathers are also given. Both sets of documents were not only found at Nippur but were obviously written there, since they closely resemble one another in general appearance, style and arrangement. The same witnesses, too, occur again and again on them, and some of the tablets, which were drawn up under different dynasties, are the work of the same scribe. It has even been found possible, by the study of the proper names, to follow the history of a family through three generations, during which it was living at Nippur under different rulers belonging to the dynasties of Nîsin, Larsa and Babylon; and one branch of the family can never have left the city, since its members in successive generations held the office of "pashishu," or anointing-priest, in the temple of the goddess Ninlil.[17]