The fantastic legends concocted by the priests go on to relate how at length Egypt was civilised by Osiris and Isis. By Osiris the people were taught agriculture; Isis weaned them from cannibalism. Osiris was slain by the red-haired and jealous demon, Sit-Typhon, and then Egypt was divided between Horus and Sit as rivals; and so it consisted henceforth of two kingdoms, of which one, that of the north, duly recognised Horus, son of Isis, as its patron deity; the other, that of the south, placed itself under the supreme protection of Sit-Nubiti, the god of Ombos. Elaborate and intricate and hopelessly confused are the fables relating to the Osirian embalmment, and to the opening of the kingdom of Osiris to the followers of Horus. Souls did not enter it without examination and trial, as it is the aim of the famous Book of the Dead to show. Before gaining access to this paradise each of them had to prove that it had during earthly life belonged to a friend or to a vassal of Osiris, and had served Horus in his exile, and had rallied to his banner from the very beginning of the Typhonian wars. To Menes of Thinis tradition ascribes the honour of fusing the two Egypts into one empire, and of inaugurating the reign of the human dynasties. But all we know of this first of the Pharaohs, beyond his existence, is practically nothing, and the stories related of him are mere legends. The real history of the early centuries eludes our researches. The history as we have it is divided into three periods: 1. The Memphite period, which is usually called the "Ancient Empire," from the First to the Tenth dynasty: kings of Memphite origin were rulers over the whole of Egypt during the greater part of this epoch. 2. The Theban period, from the Eleventh to the Twentieth dynasty. It is divided into two parts by the invasion of the Shepherds (Sixteenth dynasty). 3. Saite period, from the Twenty-first to the Thirtieth dynasty, divided again into two parts by the Persian Conquest, the first Saite period, from the Twenty-first to the Twenty-sixth dynasty; the second Saite Period, from the Twenty-eighth to the Thirtieth dynasty. _IV.--Political Constitution of Egypt_