"There are beings in the universe billions of years older than either
of our races. Once, long ago, they walked among the stars like giants,
vast and timeless. They taught the younger races, explored beyond the
rim, created great empires. But to all things there is an end. Slowly,
over a million years, the First Ones went away. Some passed beyond the
stars, never to return. Some simply disappeared."
-- Delenn, "In the Shadow of Z'Ha'Dum"