No record of a “Darius the Mede” between Belshazzar and Cyrus
Except for the Jewish historian Josephus
Josephus: "Darius the Mede, who along with his relative, Cyrus the King of Persia, brought an end to the Babylonian empire. Darius was the son of Astyages." (ass-tee-ages)
Basically, Darius the Mede was Cyrus the Great’s uncle
He wasn’t a king per-se, but he recieved the kingdom
Perhaps he was Cyrus’ General, Gubaru
Darius could be a title (means “holder of the sceptre”)