Darius the Mede
Whether the Darius who receives the kingdom is otherwise known to history or is a literary figure for the narrative.
Daniel 5:30-31
30In that night Belshazzar the Chaldean King was slain.
31Darius the Mede received the kingdom, being about sixty-two years old.
What each tradition says
Rabbinic / Midrashic
The cited article holds that Ahasuerus, father of Darius “of the seed of the Medes,” is as unknown to history as his son. It suggests both are probably the confused ideas about Persian kings of a badly informed writer.
Gerson B. Levi, Kaufmann Kohler, George A. Barton, Ahasuerus (Jewish Encyclopedia, 1901-1906) — Article 'Ahasuerus', closing historical discussion
Patristic
No sourced position found. Checked CCEL ANF vol. 5 (Hippolytus' fragments on Daniel treat the ram and leopard visions — Darius the Persian — nothing on Daniel 5:31); the ANF/NPNF corpus on New Advent; Jerome's Commentary on Daniel has no public-domain English translation (Latin editions and Archer's 1958 version only). No patristic statement on the identity of Darius the Mede found.
Catholic
Haydock's commentary states that Darius is called Cyaxares by historians, the son of Astyages, and uncle to Cyrus and to Baltassar by the mother's side. It says he is styled Astyages or Artaxerxes and takes the title king of both the Medes and Persians.
George Leo Haydock, George Haydock's Catholic Bible Commentary (1859) — On Daniel 5:31
Orthodox
No sourced position found. Checked archive.org (2026-09-14) — no public-domain English Daniel commentary (Theophylact/Euthymius English only modern and copyrighted; Greek/Latin editions only); CCEL ANF/NPNF (no Eastern treatment of Daniel 5); pravoslavieto.com (no English verse commentary); Philaret and the Synod of Jerusalem (doctrinal only). No Eastern comment on Darius the Mede's identity found.
Reformed / Protestant
Matthew Henry says Darius the Mede took the kingdom in partnership with Cyrus, by Cyrus's consent, since Cyrus had conquered it. They were partners in war, conquest, and dominion. Henry notes Darius was sixty-two, so Cyrus his nephew gave him the precedency.
Matthew Henry, Commentary on the Whole Bible Volume IV (Isaiah to Malachi) — On Daniel 5:31
Evangelical
Jamieson, Fausset, and Brown identify Darius the Median as Cyaxares II, son and successor of Astyages, 569-536 B.C. They say Cyrus led the assault, but all was done in Darius's name, so only Darius is mentioned. This shows Daniel was not ignorant of Cyrus's share in the capture of Babylon.
Robert Jamieson, A. R. Fausset, David Brown, Commentary Critical and Explanatory on the Whole Bible — On Daniel 5:31