During this period the Semitized mountaineers to the north-east of Babylonia became the most aggressive opponents of the city states. The two most prominent were the Gutium, or men of Kutu, and the Lulubu. Naram Sin's great empire included the whole of Sumer and Akkad, Amurru and northern Palestine, and part of Elam, and the district to the north. He also penetrated Arabia, probably by way of the Persian Gulf, and caused diorite to be quarried there. One of his steles, which is now in the Imperial Ottoman Museum at Constantinople, depicts him as a fully bearded man with Semitic characteristics. During his lifetime he was deified--a clear indication of the introduction of foreign ideas, for the Sumerians were not worshippers of kings and ancestors. Naram Sin was the last great king of his line. Soon after his death the power of Akkad went to pieces, and the Sumerian city of Erech again became the centre of empire. Its triumph, however, was shortlived. After a quarter of a century had elapsed, Akkad and Sumer were overswept by the fierce Gutium from the north-eastern mountains. They sacked and burned many cities, including Babylon, where the memory of the horrors perpetrated by these invaders endured until the Grecian Age. An obscure period, like the Egyptian Hyksos Age, ensued, but it was of comparatively brief duration. When the mists cleared away, the city Lagash once more came to the front, having evidently successfully withstood the onslaughts of the Gutium, but it never recovered the place of eminence it occupied under the brilliant Ur-Nina dynasty. It is manifest that it must have enjoyed under the various overlords, during the interval, a considerable degree of independence, for its individuality remained unimpaired. Of all its energetic and capable patesis, the most celebrated was Gudea, who reigned sometime before 2400 B.C. In contrast to the Semitic Naram Sin, he was beardless and pronouncedly Sumerian in aspect. His favoured deity, the city god Nin-Girsu, again became prominent, having triumphed over his jealous rivals after remaining in obscurity for three or four centuries. Trade flourished, and the arts were fostered. Gudea had himself depicted, in one of the most characteristic sculptures of his age, as an architect, seated reverently with folded hands with a temple plan lying on his knees, and his head uplifted as if watching the builders engaged in materializing the dream of his life. The temple in which his interests were centred was erected in honour of Nin-Girsu. Its ruins suggest that it was of elaborate structure and great beauty. Like Solomon in later days, Gudea procured material for his temple from many distant parts--cedar from Lebanon, marble from Amurru, diorite from Arabia, copper from Elam, and so forth. Apparently the King of Lagash was strong enough or wealthy enough to command respect over a wide area.