MORE than a thousand years have rolled away since a castle looked down cheerfully from a height amid the Franconian plains into the well-watered Kinzig Valley, with its pleasant villages and towns. It belonged to the powerful Swabian duke Frederick of Hohenstaufen, whose young and valiant son loved this the best of all his father's proud castles, and often left his uncle's splendid palace to hunt in its forests, or to look down from its lofty oriel window on the blooming plain below. His father and uncle indeed missed him sadly. His clear blue eye, and the cheerful expression of his noble countenance, seemed to the two grave and war-weary men so gladdening to look upon, that they were always unwilling to let him leave them. But the young Frederick used to beg them so earnestly to grant him the freedom of the forest for just this once, that father and uncle smilingly granted him permission, though "this once" was often repeated..