In the Egyptian 18th Dynasty the mother of "Joshua" was the daughter of Joseph. That is Queen Tiye was the mother of Tutankhamun (as "incarnation" of Joshua) and the daughter of Yuya (as "incarnation" of Joseph).
The basic relationships of the 18th Dynasty were copied as best possible by the Herodians. For example, Mariamne the daughter of Joseph and Olympias became the mother of Jesus/Aristobulous (the "incarnation" of Joshua in his day).
There were also three prominent Joseph's at the beginning of Herod's reign. The first was Herod's brother Joseph. The second was Herod's father-in-law and the third was a prominent minister. There is some confusion between these later two in the writings of Josephus as indicated in the Jewish Encylopedia. Joseph the brother of Herod was the father of a fourth Joseph, the husband of Olympias.
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