Dragons lived with humans once, in a far away land.
The people there were peaceful and learned to coexist with the great beasts. But dragons have a powerful magic, and humans could not live with them long unchanged.
They grew taller, fairer. They lived longer, and came to have magic of their own.
Other humans, seeing these changes, were afraid. They forced the dragons and their friends away, to other parts of the land. Upset by the consequences of living with dragons, some of the former humans grew violent, determining to win their homes back by force, if necessary. Friend turned against friend, and the dragons left, distressed by the troubles they had inadvertently caused.
They came to a new land, but did not mingle so close to the people there, for they wanted never to cause such troubles again.