Gudea's reign may be regarded as marking a revival of Sumerian prosperity, consequent on the decay of Semitic influence and power in the north. The fact that he was able to import his wood and stone from Syria, and float it unmolested down the Euphrates, argues a considerable weakening of the northern cities. Whether Akkad, or some other city, still claimed a nominal suzerainty over the southern districts it is impossible to say, but it is at least clear that in the reign of Gudea no such claim was either recognized or enforced. We may suppose that Lagash and the other great cities in the south, relieved from the burden of Semitic domination, enjoyed a period of peace and tranquillity, which each city employed for the development of her material resources. The city of Ur was soon to bring this state of affairs to a close, by claiming the hegemony among the southern cities and founding the kingdom of Sumer and Akkad by force of arms. But during Gudea's reign Ur appears to have made no movement, and Lagash and the other great cities of the land may be pictured as maintaining commercial relations with each other, unhampered by the striving of any one of them for political supremacy. It is possible that we may trace the unparalleled building activity, which characterized Gudea's reign, in part to a development in the art of building, which appears to have taken place at about this period. It has been suggested that both Gudea and Ur-Engur, the founder of the Dynasty of Ur, participated in the same great architectural movement,[21] and proof of this has been seen in their common employment of the smaller square brick, measuring from about twelve to thirteen inches, which was more easy to handle than the larger bricks employed by Ur-Bau and at the time of the Dynasty of Akkad. The inherent advantages of this form of brick are attested by its retention, with but slight variations, down to the end of the Babylonian empire. That Gudea himself set considerable store by the form of the bricks which he employed would seem to follow from the passage in his first cylinder-inscription, where he describes the ceremonies with which he inaugurated their manufacture, including the offer of sacrifices and the pouring of a libation into the sacred mould.[22] The use of an improved material may well have incited him to rebuild the greater number of the sanctuaries in Lagash on their ancient sites, but enlarged and beautified in accordance with the new architectural ideas. From another passage in his texts it would seem that he definitely claimed to have inaugurated a novel form of building, or decoration, such as no patesi before him had employed.[23] The meaning of the phrase is not quite certain, but it may, perhaps, have reference to the sculptured reliefs with which he adorned E-ninnû. It may also refer to the use of raised pilasters for the adornment of facades and external walls, a form that is characteristic of later