The historian of ancient Babylonia has reason to be grateful to Shutruk-Nakhkhunte and his son for their raids into the Euphrates valley, since certain of the monuments they carried off as spoil have been preserved in the mounds of Susa, until the French expedition brought them again to light. Thanks to Babylon's misfortunes at this time, we have recovered some of her finest memorials, including the famous Stele of Narâm-Sin, Hammurabi's Code of Laws, and an important series of the Kassite kudurrus, or boundary-stones, which, as we have seen, throw considerable light upon the economic condition of the country. These doubtless represent but a small proportion of the booty secured by Elam at this period, but they suffice to show the manner in which the great Babylonian cities were denuded of their treasures. Under the earlier kings of the Fourth Dynasty it would seem that Elam continued to be a menace, and it was not until the reign of Nebuchadnezzar I. that the land was freed from further danger of Elamite invasion. We possess two interesting memorials of his successful campaigns, during which he not only regained his own territories, but carried the war into the enemy's country. One is a charter of privileges, which the king conferred upon Ritti-Marduk, the Captain of his chariots, for signal service against Elam. The text is engraved on a block of calcareous limestone, and on one side of it are a series of divine symbols, sculptured in high relief, in order to place the record under the protection of the gods, in accordance with the custom introduced during the Kassite period. The campaign in Elam which furnished the occasion for the charter was undertaken, according to the text,[1] with the object of "avenging Akkad," that is to say, in retaliation for the Elamite raids in Northern Babylonia. The campaign was conducted from the frontier city of Dêr, or Dûr-ilu, and, as it was carried out in the summer, the Babylonian army suffered considerably on the march. The heat of the sun was so great that, in the words of the record, the axe burned like fire, the roads scorched like flame, and through the lack of drinking-water "the vigour of the great horses failed, and the legs of the strong man turned aside." Ritti-Marduk, as Captain of the chariots, encouraged the troops by his example, and eventually brought them to the Euheus, where they gave battle to the Elamite confederation which had been summoned to oppose them.