After the conquest of Babylon by the Persian Empire, Cyrus the Great allowed the exiled part of the Jewish population to return to their native land and rebuild Jerusalem, sacked by Nebuchadnezzar II in 586 BC.
[1] This citadel is the Birah (Hebrew: בירה) referred to in Nehemiah 2:8, 7:2, appearing as the Baris in Greek translations of the Septuagint.
In 301 BC Ptolemy I Soter, who four years earlier had crowned himself King of Egypt, exploited events surrounding the Battle of Ipsus to take control of the region.
In one section, the author, supposedly an Alexandrian Jew in the service of Ptolemy II Philadelphus (309 BC – 246 BC), visits the Temple Mount and is then invited to visit the Baris as well: But in order that we might gain complete information, we ascended to the summit of the neighbouring citadel and looked around us.
On the towers of the citadel engines of war were placed and different kinds of machines, and the position was much higher than the circle of walls which I have mentioned.
[6] It is not entirely clear when the Letter of Aristeas was written, although it is certainly much younger than the time of its supposed creation, in the middle of the 3rd century BC.
Opinions differ on the exact date, although current research suggests the middle of the 2nd century BC.
Thus the Letter of Aristeas may or may not preserve a genuine account of the citadel which stood in Jerusalem during Ptolemaic rule.
Once that citadel had been built in a location that would allow it to control and harass the Jewish population of Jerusalem, at the time occupying the City of David, the old and defunct Baris may have been taken apart.