The name ‘Mithredat’ actually comes from Persia: the treasurer of King Syrus was called this way. Silly me forgot to attach the last H but I like it better that way. I don’t really use it as a nickname though (no one calls me that way), but rather as a user name for about a million of things.
Also Cyrus the king brought forth the vessels of the house of The Lord, which Nebuchadnezzar had brought forth out of Jerusalem, and had put them in the house of his gods; Even those did Cyrus king of Persia bring forth by the hand of Mithredath the treasurer, and numbered them unto Sheshbazzar, the prince of Judah” (Ezra I:7-8)
