Daniel
Daniel 5:31BSB·traditional attribution

and Darius the Mede received the kingdom at the age of sixty-two.

John Calvin Reformed @genevareformer

Daniel adds, the kingdom was transferred to the king of the Medes, whom he calls Darius, but Xenophon terms him Cyaxares. It is clear enough that Babylon was taken by the skill and under the auspices of Cyrus; since he was a persevering warrior possessed of great authority, though he is not mentioned here.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. The death of the king. Reason enough he had to tremble, for he was just falling into the hands of the king of terrors, Dan 5:30. In that night, when his heart was merry with wine, the besiegers broke into the city, aimed at the palace; there they found the king, and gave him his death's wound.

Commenting on Daniel 5:30-31

John Gill Reformed Baptist @doctorgill

And Darius the Median took the kingdom,.... This was Cyaxares the son of Astyages, and uncle of Cyrus; he is called the Median, to distinguish him from another Darius the Persian, that came after, Ezr 4:5, the same took the kingdom of Babylon from Cyrus who conquered it; he took it with his consent, being the senior prince and his uncle.