Daniel 1:21

Cyrus : the Persian king of Babylon known as Cyrus the Great (OS)

Daniel : the prophet who wrote the book of Daniel,son of David and Abigail,head of clan (Ithamar Levi) who pledged to obey God's law,prophet who wrote the book of Daniel

Daniel 2:13

Daniel : the prophet who wrote the book of Daniel,son of David and Abigail,head of clan (Ithamar Levi) who pledged to obey God's law,prophet who wrote the book of Daniel

Daniel 4:28

Nebuchadnezzar : the king of Babylon who took Judah into exile

Daniel 5:30

Belshazzar : the deputy king of Babylon after Nebuchadnezzar