Thalia   

Babylonians, seeing that his deeds were as brave as his words, were
beyond measure pleased, and set no bounds to their trust. He waited,
however, and when the next period agreed on had elapsed, again with
a band of picked men he sallied forth, and slaughtered the two
thousand. After this second exploit, his praise was in all mouths.
Once more, however, he waited till the interval appointed had gone by,
and then leading the troops to the place where the four thousand were,
he put them also to the sword. This last victory gave the finishing
stroke to his power, and made him all in all with the Babylonians:
accordingly they committed to him the command of their whole army, and
put the keys of their city into his hands.
Darius now, still keeping to the plan agreed upon, attacked the
walls on every side, whereupon Zopyrus played out the remainder of his
stratagem. While the Babylonians, crowding to the walls, did their
best to resist the Persian assault, he threw open the Cissian and
the Belian gates, and admitted the enemy. Such of the Babylonians as
witnessed the treachery, took refuge in the temple of Jupiter Belus;
the rest, who did not see it, kept at their posts, till at last they
too learnt that they were betrayed.
Thus was Babylon taken for the second time. Darius having become
master of the place, destroyed the wall, and tore down all the
gates; for Cyrus had done neither the one nor the other when he took
Babylon. He then chose out near three thousand of the leading
citizens, and caused them to be crucified, while he allowed the
remainder still to inhabit the city. Further, wishing to prevent the
race of the Babylonians from becoming extinct, he provided wives for
them in the room of those whom (as I explained before) they strangled,
to save their stores. These he levied from the nations bordering on
Babylonia, who were each required to send so large a number to
Babylon, that in all there were collected no fewer than fifty
thousand. It is from these women that the Babylonians of our times are
sprung.
As for Zopyrus, he was considered by Darius to have surpassed,
in the greatness of his achievements, all other Persians, whether of
former or of later times, except only Cyrus- with whom no Persian ever
yet thought himself worthy to compare. Darius, as the story goes,
would often say that "he had rather Zopyrus were unmaimed, than be
master of twenty more Babylons." And he honoured Zopyrus greatly; year
by year he presented him with all the gifts which are held in most
esteem among the Persians; he gave him likewise the government of
Babylon for his life, free from tribute; and he also granted him
many other favours. Megabyzus, who held the command in Egypt against
the Athenians and their allies, was a son of this Zopyrus. And
Zopyrus, who fled from Persia to Athens, was a son of this Megabyzus.