Darius I becomes king of Persia.
Note that Cyrus’s two sons are killed in the bloodshed surrounding Darius’s ascent to power.
Darius, who will battle on all fronts, reigns for 36 tempestuous years. Among other exceptional legacies, he constructs the legendary capital of Persepolis, and expands the empire from the Indus River on the east to the border of Macedonia (Greece) on the west.
Darius is known, as well, for acute financial, legal and organizational skills. One hundred and eleven postal stations are set up with horses and riders, the first “pony express.” Darius organizes the empire into twenty provinces, each under a separate governor or satrap.
The Achaemenid Dynasty generally bans slavery over the breadth of its span.
As noted, under Darius, Daniel, back in Babylon, holds the position of the first–among–equals of the “Three President” supreme administrative office. That is, Darius effectively puts a Jew (a Jewish exile and prophet, no less) in charge of former Babylon (which had conquered and exiled the Jews in the first place).
Darius designates to Zerubaval, a (Jewish) Persian satrap in charge of Judea, the work of rebuilding the Temple. The work is carried to completion and consecration by the year 515 BCE under the stimulus of the prophets Haggai and Zechariah.
But there are items permanently missing from the First Temple, including the core and iconic crown jewels, the Ark of the Covenant, and the Ten Commandments. Their fate, a mystery for all time….
Five–hundred years later, c. 19 BCE, Herod effects an extraordinary overhaul, renovation and expansion of Temple II.
Note: The Achaemenid Dynasty had effectively incubated the Babylonian Talmud.