Daniel 5:31

“And Darius the Median took the kingdom, etc.] 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, (<150405>Ezra 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. Darius reigned not long, but two years; and not alone, but Cyrus with him, though he is only mentioned. Xenophonf227 says, that Cyrus, after he took Babylon, set out for Persia, and took Media on his way; and, saluting Cyaxares or Darius, said that there was a choice house and court for him in Babylon, where he might go and live as in his own:…”

“Darius the Median--that is Cyaxares II, the son and successor of Astyages, 569-536 B.C. Though Koresh, or Cyrus, was leader of the assault, yet all was done in the name of Darius; therefore, he alone is mentioned here; but Dan 6:28 shows Daniel was not ignorant of Cyrus' share in the capture of Babylon. Isa 13:17; Isa 21:2, confirm Daniel in making the Medes the leading nation in destroying Babylon. So also Jer 51:11, Jer 51:28. HERODOTUS, on the other hand, omits mentioning Darius, as that king, being weak and sensual, gave up all the authority to his energetic nephew, Cyrus [XENOPHON, CyropÃ&brvbrdia, 1.5; 8.7]. threescore and two years old--This agrees with XENOPHON [CyropÃ&brvbrdia,…”

“And Darius the Median took the kingdom - The city and kingdom were actually taken by Cyrus, though acting in the name and by the authority of Darius, or Cyaxares, who was his uncle. For a full explanation of the conquests of Cyrus, and of the reason why the city is said to have been taken by Darius, see the notes at Isaiah 41:2. In regard to the question who Darius the Median was, see the Introduction to Daniel 6:0, section II. The name Darius - דריושׁ dâreyâvêsh, is the name under which the three Medo-Persian kings are mentioned in the Old Testament. There is some difference of opinion as to its meaning. Herodotus (vi. 98) says, that it is equivalent to ἑρξίης herxiēs, “one who…”

“Darius the Mede - This was he that with Cyrus besieged and took Babylon. Next: Daniel Chapter 6”

“5:31 Darius the Mede is distinct from later Persian kings named Darius (see “The Medes and Persians” Profile). Cyrus the Great conquered Babylon in 539 BC, and there is no mention of a Darius the Mede in other sources. Two solutions are possible: (1) Cyrus the Great might have appointed Darius the Mede to rule as “King of Babylon” in his place for a little over a year (cp. Dan 6:28; 9:1; 11:1); or (2) Darius and Cyrus might have been the same man bearing two throne names—one name from the Medes, the other from the Persians (see also study note on 6:28). The portrayal of Darius in ch 6 suggests that he was in fact Cyrus, the ruler of all Media, Persia, and Babylonia.”

“Darius: This was Cyaxares, son of Astyages, king of Media, and maternal uncle to Cyrus, who allowed him the title of his conquests, as long as he lived. Dan 6:1, Dan 9:1 being: Chal, he as the son of, etc about: or, now Next: Daniel Chapter 6”

“With the death of Belshazzar that very night the interpretation given by Daniel began to be fulfilled, and this fulfilment afforded a certainty that the remaining parts of it would also sooner or later be accomplished. That this did not take place immediately, we have already shown in our preliminary remarks to this chapter. Next: Daniel Chapter 6”