Question: Which ruler unwilling had Daniel thrown into the lion’s den?
Comments: In the famous story of Daniel surviving the Lion's Den, the ruler who ordered Daniel's punishment was Darius the Mede. Darius is the third ruler listed in the Book of Daniel and his inclusion has been problematic for historians. Historically "Darius the Mede" is mentioned in only in relation to this story in the book of Daniel, the writings of Jewish historian Flavius Josephus (370-100), and Jewish Midrash material. Otherwise, he is not known from any primary historical sources.
So Darius the Mede received the kingdom at about the age of sixty-two. (Daniel 5:31, NASB)
There have been numerous apologetic approaches to Darius, all of which entail renaming the otherwise unknown Darius the Mede as some known figure from the time.
Note: this portrait of Daniel was created by Phillip Ratner.