Involved with Ezra in the re-building of the First Temple, at around 516 B.C.E. One of the Books of the “TANACH,” the Hebrew Bible, is named after him, and gives an historical account of his time.
He was brought with his companions Chananiah, Mishael and Azariah to the royal court of Nevuchadnezzar. There he and they refuse to eat the king’s food (because it is not Kosher (no OU!)), and they subsist on a meager diet. Nevertheless, HaShem miraculously keeps them hale and hearty, as they prove to the Minister of the King responsible for their care.
HaShem protects Daniel from harm when he is thrown into a lions’ den, because he has been discovered praying to HaShem and facing towards Jerusalem.