The whole of the period in a sense culminated in the great Ramessu II, the oppressor of the Hebrews, who with his Egyptian, Libyan, and Negro armies fought half the world. His reign, however, was the beginning of decline, and foes began to press Egypt from the white north and the black south. The priests transferred their power at Thebes, while the Assyrians under Nimrod overran Lower Egypt. The center of interest is now transferred to Ethiopia, and we pass to the more shadowy history of that land. The most perfect example of Egyptian poetry left to us is a celebration of the prowess of Usertesen III in confining the turbulent Negro tribes to the territory below the Second Cataract of the Nile. The Egyptians called this territory Kush, and in the farthest confines of Kush lay Punt, the cradle of their race. To the ancient Mediterranean world Ethiopia (i.e., the Land of the Black-faced) was a region of gods and fairies. Zeus and Poseidon feasted each year among the "blameless Ethiopians," and Black Memnon, King of Ethiopia, was one of the greatest of heroes. "The Ethiopians conceive themselves," says Diodorus Siculus (Lib. III), "to be of greater antiquity than any other nation; and it is probable that, born under the sun's path, its warmth may have ripened them earlier than other men. They suppose themselves also to be the inventors of divine worship, of festivals, of solemn assemblies, of sacrifices, and every religious practice. They affirm that the Egyptians are one of their colonies." The Egyptians themselves, in later days, affirmed that they and their civilization came from the south and from the black tribes of Punt, and certainly "at the earliest period in which human remains have been recovered Egypt and Lower Nubia appear to have formed culturally and racially one land."[13] The forging ahead of Egypt in culture was mainly from economic causes. Ethiopia, living in a much poorer land with limited agricultural facilities, held to the old arts and customs, and at the same time lost the best elements of its population to Egypt, absorbing meantime the oncoming and wilder Negro tribes from the south and west. Under the old empire, therefore, Ethiopia remained in comparative poverty, except as some of its tribes invaded Egypt with their handicrafts. As soon as the civilization below the Second Cataract reached a height noticeably above that of Ethiopia, there was continued effort to protect that civilization against the incursion of barbarians. Hundreds of campaigns through thousands of years repeatedly subdued or checked the blacks and brought them in as captives to mingle their blood with the Egyptian nation; but the Egyptian frontier was not advanced.