Daniel 9:1

In the first year of Darius, son of Ahasuerus, of the seed of the Medes, who hath been made king over the kingdom of the Chaldeans,

Daniel 11:1

And I, in the first year of Darius the Mede, my standing is for a strengthener, and for a stronghold to him;

Daniel 1:21

And Daniel is unto the first year of Cyrus the king.

Daniel 5:31-1

and Darius the Mede hath received the kingdom, when a son of sixty and two years.

Daniel 6:28

And this Daniel hath prospered in the reign of Darius, and in the reign of Cyrus the Persian.

Treasury of Scripture Knowledge

Summary

In the first year of Darius the son of Ahasuerus, of the seed of the Medes, which was made king over the realm of the Chaldeans;

Bible References

Darius

Daniel 1:21
And Daniel is unto the first year of Cyrus the king.
Daniel 5:31
and Darius the Mede hath received the kingdom, when a son of sixty and two years.
Daniel 6:1
It hath been good before Darius, and he hath established over the kingdom satraps -- a hundred and twenty -- that they may be throughout the whole kingdom,
Daniel 11:1
And I, in the first year of Darius the Mede, my standing is for a strengthener, and for a stronghold to him;