From what we know of the early history of Sumer, it would appear that most of its city-states were subject to alternate periods of expansion and decay; and we have already seen reason to believe that, before the reign of Urukagina, the reaction had already set in, which must inevitably have followed the conquests of the earlier patesis. The struggle for the throne, which appears to have preceded Urukagina's accession, must have weakened still further the military organization of the state; and when Urukagina himself, actuated by the best of motives, attempted to reform and remodel its entire constitution, he rendered it still more defenceless before the attack of any resolute foe. The city of Umma was not slow to take advantage of so favourable an opportunity for striking at her ancient rival. Hitherto in their wars with Lagash the men of Umma, so far as we know, had never ventured, or been allowed, to attack the city. In earlier days Umma had always been defeated, or at any rate her encroachments had been checked. It is true that in the records that have come down to us the men of Umma are represented as always taking the initiative, and provoking hostilities by crossing the frontier-ditch which marked the limit of their possessions. But they never aimed at more than the seizure of territory, and the patesi of Lagash was always strong enough to check their advance, and generally to expel them, before they reached the city itself. Indeed, Entemena had done more than this, and, by his capture and annexation of Umma, had crippled for a time the resources of this ambitious little state. At what period exactly Umma repudiated the suzerainty he had imposed is not known; but in any case we may conclude that the effects of the chastisement she had received at his hands were sufficient to prevent for a time any active encroachments on her part. The renewed activity of Umma during Urukagina's reign doubtless followed the lines of her earlier attempts, and took the form of a raid into the territory of Lagash. The comparative success, which we may conjecture she achieved on this occasion, doubtless encouraged her to further efforts, and emboldened her patesi to attack the city of Lagash itself. The ruler of Umma, under whose leadership this final attack was delivered, bore the name of Lugal-zaggisi. From an inscription of his own, to which further reference will be made in the following chapter, we learn that his father Ukush had been patesi of Umma before him. We may thus assume that the city had for some time enjoyed a position of independence, of which she had taken advantage to husband her resources and place her army on a satisfactory footing. In any case it was strong enough to overcome any opposition that Urukagina could offer, and the city of Lagash, which had been beautified and enriched by the care of a long line of successful rulers, was laid waste and spoiled.