Three of the Greek goddesses were called the Fates (or Moirae). One of them spun a thread. Her name was Clotho. The second one, Lachesis, stretched the thread out as long as she pleased. The third one, Atropos, snipped it off.
The thread was supposed to be human life. The three Fates, then, decided when a person was to be born, how long he would live, and when he would die. Not even the king of the gods, the old Greek myths said, could make the Fates change their minds.