Young nobles from the royal house of Judah. They were chosen for their beauty, intelligence, and potential to serve in the palace of Nebuchadnezzar. They were meant to be the "Elite Export" of a dying nation.
Their Hebrew names (Hananiah, Mishael, Azariah) all pointed to Yahweh. The Babylonians renamed them after their own gods (Marduk, Aku, Nego). They were formed by Identity Conflict—living with pagan names while serving the Holy God.
They were formed by Shared Resolve. In Daniel 1, they joined Daniel in refusing the King's food. They were a "Band of Brothers" who decided early on that their appetites would not rule their spirits.