There is no doubt that the union of Upper and Lower Egypt into a single monarchy, traditionally ascribed to Mena, the legendary founder of the first Egyptian dynasty, did result from a conquest of the North by the South. Mena himself was regarded as sprung from a line of local rulers established at This, or Thinis, in the neighbourhood of Abydos, and also as the founder of Memphis at the head of the Delta, whither he transferred his throne. Further traces of the conquest of the North by the South have been preserved in the legends concerning the followers of Horus, the patron deity of the first kings of Upper Egypt. The advance of the Sky-god of Edfu with his Mesniu or "Smiths,"[2] who are related to have won battle after battle as they pressed northwards, is amply confirmed by the early dynastic monuments that have been recovered by excavation. The slate carving of Narmer, on which is portrayed the victory of Horus over the kingdom of the Harpoon near the Canopic branch of the Nile, may well represent one of the last decisive victories of the Horus-worshippers, as they extended their authority northwards to the sea.[3] Of the historical character of this conquest of Lower Egypt by the kings of the South, which resulted in the union of the whole country under a single monarchy, there are now no two opinions. The point, about which some uncertainty still exists, concerns the racial character of the conquerors and the origin of their higher culture, by virtue of which their victories were obtained. On the hypothesis of a Semitic invasion, the higher elements in the early culture of Egypt are, as we have seen, to be traced to a non-Egyptian source. The Semitic immigrants are assumed to have introduced, not only the use of metal, but also a knowledge of letters. The Sumerian system of writing has been regarded as the parent of the Egyptian hieroglyphic characters; and comparisons have been made between the names of Sumerian and Egyptian gods.[4] The suggestion has also been put forward that the fashion of extended burial, which in Egypt gradually displaced the contracted position of the corpse, was also to be traced to Babylonian influence.