The name Daniel means "God is my judge." After being taken as a Jewish captive to the pagan world of Babylon, his name was changed to Belteshazzar which means "may Bel protect his life" or "prince favored by Bel" (Bel was a Babylonian god).
Jerusalem may have been his birthplace, though this is mere opinion. He was likely of royal blood, because he was among the nobles and princes taken captive by Nebuchadnezzar following the first Babylonian siege of Jerusalem in 605BC, the fourth year of Jehoiakim. He was in his mid-teens at the time, and was put into a three-year training program to serve the king of Babylon.
Daniel quickly distinguished himself through his wisdom and deep commitment to God. Recognizing that his gifts of intelligence, physical condition and wisdom came directly from God, he continually emphasized that everything we have, including popularity or political power, is a gift that can be taken away by God at any time.
Ezekiel, a Jewish prophet taken captive a few years later, used Daniel as an example of true righteousness. In a conversation with Ezekiel about the fate of Jerusalem, God places Daniel with Job and Noah in purity of faith. He says that even if these three men were in Jerusalem their righteousness would save only them and not spare the city its coming destruction.
Son of man, if a country sins against me by being unfaithful and I stretch out my hand against it to cut off its food supply and send famine upon it and kill its men and their animals, even if these three men--Noah, Daniel and Job--were in it, they could save only themselves by their righteousness, declares the Sovereign LORD.
After interpreting a dream for Nebuchadnezzar, the king promoted Daniel to a senior position. He continued to interact closely with king Nebuchadnezzar throughout his reign. Jewish tradition holds that during the king's seven years of insanity Daniel looked after him. He had such an impact on Nebuchadnezzar that the king eventually published a personal testimony as a royal affidavit of his conversion, recognizing the God of the Jews as the one and only true God.
Several kings later, Daniel still served Babylon's king, though he had no interaction at all with Belshazzar, the co-regent under Nabonidus. The end of chapter 8 suggests that he was working in some capacity for Nabonidus.
After the fall of Babylon to the Persians, Daniel so impressed the new king, Darius, that he was groomed for the position of Prime Minister. This caused considerable political turmoil. A plot by his enemies succeeded in getting him marked for execution by having him thrown into a lions' den. God miraculously spared his life.
Tradition has it that Daniel died in the Persian city of Susa which would eventually become the capital city of the Persian empire. It is believed from language structure that Daniel completed his memoirs in 532BC. His fluent use of both the Chaldean (Aramaic) and Hebrew languages are a testamant to his intelligence and wisdom. He wrote his account in both languages. The portion dealing with Gentile history was recorded in the Gentile language of the day, Aramaic, beginning and ending with a nearly identical vision given first to Nebuchadnezzar and then to Daniel. The portion dealing primarily with the Jews as the focal point was written in Hebrew.