Its classification presupposes a deeper study into the history of the Pharaohs hitherto unheard of. We have seen how, when a journeyman, Lepsius devoted himself by preference to the study of historical monuments, and while in Egypt he everywhere laid the greatest stress upon this. As a master workman too, after his return to Berlin in 1846, he remained faithful to his historical bias. He had at his disposal, in complete shape, all that was furnished by the monuments in the way of historical information. The systematic arrangement of the work on monuments which he had in view already imposed upon him the task of restoring in a critical manner the main skeleton of history, (chiefly Egyptian,) and of ascertaining the periods of time which separate the chief historical events from each other and from our own age. In other words, he was obliged to devote himself with all his energy to the study of Egyptian chronology. As a matter of course the monuments were always the foundation from which he proceeded, but it was also necessary to consult and to fix the worth of such other historical records as were in existence. Amongst these the highest rank was held by the Egyptian history of Manetho of Sebennytos. This had been written, or was said to have been written, for Ptolemy II. Philadelphus (285-247 B.C.) by Manetho, an Egyptian priest familiar with the Greek tongue. During the Christian era several other works, (the Book of Sothis and the Old Chronicle), were falsely attributed to this writer. The heathen Greeks had held the histories of the priestly scholar in little esteem, but, except by the Jew Flavius Josephus, they were diligently used by chronographers of the Christian era in their efforts to establish a chronological reckoning for the legendary and historical events in the Old Testament. Amongst these writers are found the lists of the Egyptian kings compiled by the Sebennite, with an estimate of the duration of their reigns. But there is a frequent disagreement in the facts as given by them, for each individual chronographer adapted the figures to his own system, and altered them arbitrarily to suit his special purposes. Therefore the fragmentary information gathered from Manetho as to the succession of rulers, can only be used with great prudence. Lepsius submitted these statements, as well as other accounts of Egyptian history occurring in the classics (Hecateus of Miletus, Herodotus, Hecateus of Abdera, Diodorus, etc.), to a severe criticism, in the attempt to separate the genuine work of Manetho from all that had been interpolated or perverted in his writings. As a result of Lepsius’ supposition that some of the ruling families enumerated in the lists did not reign successively, but contemporaneously, he arrived at the conclusion that Manetho would reckon the duration of Egyptian history, from the first King Menes to the end of the reign of Nectanebus II,[64] at three thousand five