Another remark is, that these authentic records of early history only begin to appear when civilization is so far advanced as to have established powerful dynasties and priestly organizations. The history of a nation is at first the history of its kings, and its records are enumerations of their genealogies, successive reigns, foundation or repair of temples, great industrial works, and warlike exploits. These are made and preserved by special castes of priestly colleges and learned scribes, and they are to a great extent precise in date and accurate in fact. Before the establishment of such historical dynasties we have nothing but legends and traditions, which are vague and mythical, the mythological element rapidly predominating as we go backwards in time, until we soon arrive at reigns of gods, and lives of thousands of years. But as we approach the period of historical dynasties the mythological element diminishes, and we pass from gods reigning 10,000 years, and patriarchs living to 900, to later patriarchs living 150 or 200 years, and finally to mortal men, living, and kings reigning, to natural ages. In fact, with the first appearance of authentic records the supernatural disappears, and the average duration of lives, reigns, and dynasties, and the general course of events, are much the same as at present, and fully confirm, the statement of the Egyptian priests to Herodotus, that during the long succession of ages of the 345 high priests of Heliopolis, whose statues they showed him in the great temple of the sun, there had been no change in the length of human life or in the course of nature, and each one of the 345 had been a _piromis_, or mortal man, the son of a _piromis_. The first question is how far back these authentic historical records can be traced, and Egypt affords the first answer. The first step in the inquiry as to Egyptian antiquity is afforded by the history of Manetho. Ptolemy Philadelphus, whose reign began 284 B.C., was an enlightened king. He founded the great Alexandrian library, and was specially curious in collecting everything which bore on the early history of his own and other countries. With this view he had the Greek translation, known as the Septuagint, made of the sacred books of the Hebrews, and he commissioned Manetho to compile a history of Egypt from the earliest times, from the most authentic temple records and other sources of information. Manetho was eminently qualified for such a task, being a learned and judicious man, and a priest of Sebennytus, one of the oldest and most famous temples.