The image and quote below depict Alexander's lineage as reconstructed in the novel, Victory's Crossing. This is a *fictional* reconstruction with the sections in gray created by the author.
However, the conflict between Alexander Janneus and Egypt as described below, including the role of Cleopatra III's Jewish General Ananias IS historical and was described by the first century historian Josephus in his Antiquities.
The fictional Alexander the Alabarch describes his lineage as such:
"... Back then [over a hundred years earlier] Rome was not a big player in the region and the existing countries were constantly engaged in conflicts ranging from border skirmishes to all out war. In particular there was a major conflict between my ancestor, Alexander Janneus, the King of Judea, and Ptolemy Lathyrus, the son of the reigning Queen of Egypt. Apparently Alexander Janneus had become emboldened by previous victories and had underestimated the Egyptian force. Ptolemy invaded and Alexander was losing badly. If nothing was done, the kingdom of the Jews would fall to Egypt.
So Alexander Janneus went to Ptolemy’s mother Cleopatra III, presented her with a number of gifts and begged for peace. Most of her advisors recommended that she disregard Alexander’s pleas and annex Judea. But as it happens, the general of Cleopatra’s army Ananias, my ancestor on the Egyptian side, was also a Jew. His father Onias IV, a high priest, had immigrated to Egypt and become the commanding general of her predecessor, Cleopatra II, and Ananias had inherited the role. Ananias convinced Cleopatra that a declaration of war on the Jews in Judea was tantamount to a declaration of war on the several hundred thousand Jews residing in Egypt. If she proceeded against Alexander Janneus, she would be warring on two fronts, external and internal.
So Cleopatra II instead made a treaty of friendship between Egypt and Judea. In gratitude for his intercession that saved Judea, Alexander Janneus married his daughter to Ananias of Egypt and she became my great grandmother.”
Although there is no historical evidence to support this particular family tree, evidence does strongly indicate that Alexander may have been descended from Judea's Hasmonean nobility and High Priests. Therefore the following reconstruction is historically possible ... perhaps even plausible ... but will remain fiction unless further evidence is found to substantiate it.