Iluma-ilum was thus afforded the opportunity of consolidating his position, and we may perhaps see evidence of his growing influence in Southern Babylonia in the fact that at Tell Ṣifr not a single document has been found dated in a later year of Samsu-iluna's reign than the tenth.[6] In view of the fact that the central city of Nippur eventually passed under Iluma-ilum's control, we may probably assume that he was already encroaching northwards, and that territory in the south of Sumer, perhaps including the city of Larsa, passed now into his possession. In support of this suggestion it may be noted that, when Samsu-iluna, after suppressing the Akkadian usurper, began repairing the damage wrought in six years of continuous fighting, it is at Nîsin and at Sippar that he rebuilds the ruined walls, and in Emutbal that he repairs the great garrison-fortresses. Nîsin may well have marked the most southerly limit of Babylon's control, and we may picture the gradual expansion of the Sea-Country, as the power of Babylon declined. The "rebellious land," which Samsu-iluna boasts that he overthrew in his twentieth year, was perhaps the Sea-Country, for we know that he conducted a second campaign against Iluma-ilum, who this time secured a victory. If the Babylonian army succeeded in retreating in comparatively good order, it would have formed a sufficient justification for Samsu-iluna's boast that he had given the rebellious land a lesson. The fringe of territory in the extreme south-east of Babylonia always exhibited a tendency to detach itself from the upper riverain districts of Babylonia proper. Forming the littoral of the Persian Gulf, and encroaching in its northern area upon Elam, it consisted of great stretches of rich alluvial soil interspersed with areas of marsh-land and swamps, which tended to increase where the rivers approached the coast. The swamps undoubtedly acted as a protection to the country, for while tracks and fords were known to the inhabitants, a stranger from the north-west would in many places have been completely baffled by them. The natives, too, in their light reed-boats could escape from one district to another, pushing along known passages and eluding their pursuers, when once the tall reeds had closed behind them. The later Assyrians at the height of their power succeeded in subduing a series of revolts in the Sea-Country, but it was only by enlisting the help of native guides and by commandeering the light canoes of neighbouring villages. The earlier kings of Babylonia had always been content to leave the swamp-dwellers to themselves, and at most to exact a nominal recognition of suzerainty. But it is probable that fresh energy had been lately introduced into the district, and of this Iluma-ilum doubtless took advantage when he succeeded, not only in leading a revolt, but in establishing an independent kingdom. [Illustration: FIG. 44. SWAMP IN SOUTHERN BABYLONIA OR THE SEA-COUNTRY.