Cross reference
Daniel 5:31
31 And Darius the Median took the kingdom, being about threescore and two years old.
Daniel 9:1
1 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;
Daniel 6:1
1 It pleased Darius to set over the kingdom an hundred and twenty princes, which should be over the whole kingdom;