I found some additional background material in the following references:
Oxford History of Ancient Egypt, Ian Shaw, ed.
Chronicle of the Pharaohs, by Peter Clayton
Harper Collins Concise Atlas of the Bible, James Pritchard, ed.
1) Ptolemy I claimed that Phillip II was his true father and that his mother was pregnant with him upon her marriage to Lagus, his father of record. If actually the case, this would have made him the half-brother of Alexander the Great. We have here the enduring tradition that a firstborn son of a young royal woman often preceded her political marriage, and this was entirely accepted. Alexander the Great made a similar claim for himself. He wanted to be considered the "son of God" rather than merely the son of Phillip II. I think for Alexander the case is very strong that he had in fact been sired by one of the Persian Great Kings that preceded Darius III, such as Artaxerxes II (a.k.a. "God" and "Zeus"). The Ptolemies also perpetuated (as at Dendera) the ancient Egyptian believe that the mother of pharaoh was visited and impregnated by God in the guise of the actual father. There are at least two examples of a brother and sister marriage among the Ptolemies. However, because of the secrecy involved in royal reproduction, we should not necessarily conclude that these were full brother-sister marriages, especially when this particular type of pairing was not preferrable in earlier Egyptian history.
2)The Ptolemies, after gaining control over Jerusalem and the Jews, were in general quite liberal toward them. This can be said for Ptolemy I-III, and again with Ptolemy V and VI. Alexander the Great had been crowned pharaoh at the temple of Ptah in Memphis. The Ptolemies remained patrons of the Memphite priesthood and increased its influence. However, we should expect that they eventually also placed one of their own in the top office as they sought to do in Jerusalem.
3) The Zenon Papyri contains a letter from a commander named Toubias in the reign of Ptolemy II. This is perhaps an archaeological record of Ptolemy Euergetes before he succeeded to kingship.
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