In all their inscriptions, too, the kings of Nîsin lay claim to the rule of Sumer and Akkad, while Ishme-Dagan and his son Libit-Ishtar[32] adopt further descriptive titles implying beneficent activities on their part in the cities of Nippur, Ur, Erech and Eridu. The recently published inscriptions of Libit-Ishtar, which were recovered during the American excavations at Nippur, prove that in his reign the central city and shrine of Babylonia were under Nîsin's active control. But he was the last king in the direct line from Ishbi-Ura, and it is probable that the break in the succession may be connected with a temporary depression in the fortunes of the city; for we shortly have evidence of an increase in the power of Larsa, in consequence of which the city of Ur acknowledged her suserainty in place of that of Nîsin. At the time of Libit-Ishtar's death Zabâia was reigning at Larsa, but after three years the latter was succeeded by Gungunum, who not only bore the titles of king of Larsa and of Ur, but laid claim to the rule of Sumer and Akkad. At any rate, one member of the old dynastic family of Nîsin acknowledged these new claims. Enannatum, Libit-Ishtar's brother, was at this time chief priest of the Moon-temple in Ur, and on cones discovered at Mukayyar he commemorates the rebuilding of the Sun-temple at Larsa for the preservation of his own life and that of Gungunum.[33] It is possible that when Ur-Ninib secured the throne of Nîsin, the surviving members of Ishbi-Ura's family fled from the city to its rival, and that Enannatum, one of the most powerful of their number, and possibly the direct heir to his brother's throne, was installed by Gungunum in the high-priestly office at Ur. It would be tempting to connect Libit-Ishtar's fall with a fresh incursion of West-Semitic tribes, who, recking little of any racial connexion with themselves on the part of the reigning family at Nîsin may have attacked the city with some success until defeated and driven off by Ur-Ninib. We now know that Ur-Ninib conducted a successful campaign against the Su tribes on the west of Babylonia,[34] and in support of the suggestion it would be possible to cite the much discussed date-formula upon a tablet in the British Museum, which was drawn up in "the year in which the Amurru drove out Libit-Ishtar."[35] But since the Libit-Ishtar of the formula has no title, it is also possible to identify him with a provincial governor, probably of Sippar, who bore the name of Libit-Ishtar, and seems to be referred to on other documents inscribed in the reign of Apil-Sin, the grandfather of Hammurabi.[36] The date assigned to the invasion on the second alternative would correspond to another period of unrest at Nîsin, which followed the long reign of Enlil-bani, so that on either alternative we may conjecture that the city of Nîsin was affected for a time by a new incursion of Amorites.