The Princess and the Glass Mountain
  
  There was once a king, who was so devoted to the chase that he knew of no
  greater pleasure than hunting the beasts of the forest. Early and late he would stay out
  in the field with hawk and hound, and always had good success. It nevertheless one day
  happened that he could find no game, though he sought on all sides from early morn. 
  When evening was drawing on, and he was about to return home with his attendants, he
  suddenly saw a dwarf, running before him in the forest. The king instantly gave chase, and
  soon caught him. His extraordinary appearance caused much surprise, for he was little and
  ugly as a Troll, and his hair resembled shaggy moss. To whatever the king said to him he
  would return no answer, good or bad. At this the king was angry, and the more so as he was
  already in a bad temper, due to his bad luck at the chase. He therefore commanded his
  followers to keep a strict watch over the wild man, so that he might not escape, and then
  returned to his palace. 
  One evening, as the king and his men were drinking and making themselves merry, the
  king, taking up a large horn, said: "What think ye of our sport to day? When could it
  before have been said of us, that we returned home without some game?" The men
  answered: "It is certainly true as you say, and yet, perhaps, there is not so good a
  sportsman as you to be found in the whole world. You must not, however, complain of our
  day's luck, for you have caught an animal, whose like was never before seen or heard
  of." This pleased the king exceedingly, and he asked what they thought he had best do
  with the wild man. One of the courtiers answered: "You should keep him confined here
  in the palace, that it may be known far and near what a great hunter you are; provided
  that you can guard him so that he does not escape; for he is a crafty creature." On
  hearing this, the king for some time sat silent; then raising the horns said: "I will
  do as you say and it shall be through no fault of mine, if the dwarf escapes. But this I
  vow, that if any one lets him loose, he shall die, even if it be my own son." Having
  said this, he emptied the horn, so that it was an unbreakable oath. But the courtiers cast
  looks of doubt on each other; for they had never before heard the king so speak, and could
  plainly see that the drink had gone to his head. 
  On the following morning, when the king awoke, he remembered the vow he had made at the
  drinking party, and sent for timber and other materials, and caused a small cage to be
  constructed close by the royal palace. The cage was formed of large beams, and secured by
  strong locks and bars, so that no one could break through. In the middle of the wall there
  was a little opening or window, for the purpose of bringing food to the prisoner. When all
  was ready, the king had the wild man brought forth, placed him in the cage, and took the
  keys himself. There sat the wild man both day and night, with goers and comers stopping to
  gaze on him; but no one ever heard him complain, or even utter a single word. 
  After some time passed, a war broke out, and the king was obliged to take the field. On
  the eve of departure, he said to his queen: "You shall rule over my realm, and I will
  leave both land and people in your care. But you shall promise me one thing, that you will
  keep the wild man, so that he escape not while I am away." The queen promised to do
  her best both in that and all things besides; and the king gave her the keys of the cage.
  He then pushed his barks from the shore, hoisted sail on the gilded yards, and went far,
  far away to distant countries; and to whatever place he came, he was there victorious. But
  the queen stood on the share, looking after him as long as she could see his banners
  waving over the ocean, and then, with her attendants, returned to the palace, there to sit
  sewing silk on her knee, awaiting her husband's return. 
  The king and queen had an only child, a prince, still of tender age, but who gave good
  promise of himself. After the king's departure, it one day happened that the boy, in his
  wanderings about the palace, came to the wild man's cage, and sat down close by it playing
  with his gold apple. While he was thus amusing himself, his apple chanced to pass through
  the window of the cage. The wild man came forward and threw it out. The boy thought this a
  pleasant game, and threw his apple in again, and the wild man threw it back, and thus they
  continued for some time. But at length pleasure was turned to sorrow, for the wild man
  kept the apple and would not throw it back. When neither threats nor pleading were of any
  use, the child burst into tears. Seeing this, the wild man said: "Your father has
  acted wickedly towards me, in making me a prisoner, and you shalt never get thy apple
  again, unless you set me free." 
  The boy answered: "How shall I set you free? Only give me my gold apple! my gold
  apple!" 
  "You must do as I now tell you," replied the wild man. "Go to the queen,
  your mother, and ask her to comb your hair. Be on the watch, and steal the keys from her
  belt, then come and open the door. You can afterwards put back the keys in the same
  manner, and no one will be the wiser." Soon, the wild man succeeded in persuading the
  boy, who stole the keys from his mother, ran down to the cage, and let the wild man come
  out. At parting, the wild man said: "Here is thy gold apple, as I promised, and you
  have my thanks for allowing me to escape. Some time, when you are in trouble, I will help
  you in return." He then ran off. 
  When it was known in the royal palace that the wild man had fled, there was a great
  commotion; the queen sent people on the roads and ways to track him; but he was away and
  continued away. Thus some time passed, and the queen was more and more troubled, for she
  was in daily expectation of her husband's return. At last she saw his ships come dancing
  on the waves, and a multitude of people were assembled on the shore to bid him welcome. 
  On landing, his first inquiry was, whether they had taken good care of the wild man;
  when the queen had to confess what had happened. At this news the king was greatly
  angered, and declared he would punish the guilty one, whoever he might be. He then caused
  a search to be made throughout the palace and every man's child was called forth to bear
  witness; but no one knew anything. 
  At last the little prince came forward. On appearing before his father he said: "I
  know that I have made you angry; but I cannot hide the truth, for it was I who let the
  wild man escape." On hearing this the queen grew deadly pale, and every other with
  her; for the little prince was the favorite of all. At length the king spoke: "Never
  shall it be said of me that I broke my vow, even for my own flesh and blood; and you shall
  surely die as you deserve." Thereupon he gave orders to his men to convey the young
  prince to the forest, and there slay him; but to bring his heart back, as a proof that his
  order had been carried out. 
  Now there was sorrow among the people such as the like had never before been
  experienced; every one interceded for the young prince, but the king's word was final. The
  young men had, therefore, no alternative; so taking the prince with them, they set out on
  their way. When they had penetrated very far into the forest, they met a man driving
  swine; whereupon one of the men said to his companion: "It seems to me not good to
  lay violent hands on a king's son: let us rather purchase a hog, and take its heart; for
  no one will know it not to be the prince's heart." This to the other seemed wisely
  said; so they bought a hog from the man, slaughtered it, and took out its heart. They then
  told the prince go his way and never return. 
  The king's son did as they had directed him; he wandered on as far as he was able, and
  had no other food than the nuts and wild berries which grew in the forest. When he had
  thus traveled a long distance, he came to a mountain, on the summit of which stood a lofty
  fir tree. He then thought to himself: "I will climb up into this fir, and see whether
  there is any path." No sooner said than done. When he reached the top of the tree,
  and looked on all sides, he discerned a spacious palace lying at a great distance, and
  glittering in the sun. At this sight he was overjoyed, and instantly bent his steps there.
  On his way he met with a boy following a plough, with whom he exchanged clothes. Thus
  equipped he at length reached the palace, entered it, and asked for work; so was taken as
  a herd-boy, to watch the king's cattle. Now he ranged about the forest both late and
  early; and as time went on he forgot his sorrow, and grew tall and vigorous, so that
  nowhere was to be found his like. 
  Our story now turns to the king, to whom the palace belonged. He had been married, and
  by his queen had an only daughter. She was much fairer than other damsel, and was both
  kind and courteous; so that he might be regarded as fortunate, who should one day win her
  hand. 
  When she had completed her fifteenth winter, she had an innumerable host of suitors,
  whose number was constantly increasing; so that the king at length knew not what answer to
  give them. He one day, therefore, went up to his daughter in her bower, and desired her to
  make a choice, but she would not. In his anger at her refusal he said: "As you will
  not yourself make a choice, I will make one for you, although it may happen not to be
  altogether to your liking." He was then going away, but his daughter held him back,
  and said: "I believe that it must be as you wish; but, you must not imagine that I
  will accept the first that is offered, as he alone shall possess me, who is able to ride
  to the top of the high glass mountain fully armed." This the king thought a good
  idea, and, yielding to his daughter's resolution, he sent a proclamation over the whole
  kingdom, that whosoever should ride fully armed to the top of the glass mountain, should
  win the princess for his wife. 
  When the day appointed by the king had arrived, the princess was taken to the glass
  mountain with great pomp and splendor. There she sat, the highest of all, on the top of
  the mountain, with a golden crown on her head and a golden apple in her hand. At the
  mountain's foot were assembled all the suitors on noble horses and with splendid arms,
  which shone like fire in the sunshine; and from every quarter the people flocked in great
  crowds to see the spectacle. When all was ready, a signal was given with horns and
  trumpets, and in the same instant the suitors galloped up the hill one after another. But
  the mountain was high, and slippery as ice, and was, moreover, exceedingly steep; so that
  each suitor had ascended only a small way when he fell headlong to the bottom. You may
  well imagine that there was no lack of broken legs and arms. There arose a such a noise
  from the neighing of horses, the outcry of people and the crash of armor that it was heard
  at a considerable distance. 
  While all this was passing, the young prince was occupied in tending his cattle. On
  hearing the tumult and the rattling of arms, he sat on a stone, rested his head on his
  hand, and wept; for he thought of the beautiful princess, and it passed in his mind how
  gladly he would have been one of the riders. In the same moment he heard the sound of a
  footstep, and, on looking up, saw the wild man standing before him. Thanks for the
  past," said he. "Why do you sit here lonely and sad?" 
  "I may well be sad," answered the prince. "For thy sake I am a fugitive
  from my native land, and have now not even a horse and arms, with which I might ride to
  the glass mountain, and contend for the princess." 
  "Oh," said the wild man, "if that's all, a remedy may easily be found.
  You have helped me, I will now help you in return." 
  Then, taking the prince by the hand, he led him to his cave deep down in the earth, and
  showed a suit of armor hanging on the wall, forged of the hardest steel, and so bright
  that it shed a bluish light all around. Close by it stood a splendid steed, ready saddled
  and bridled, and champing his bit. The wild man then said to him: "Arm yourself
  quickly, and ride away, and try your fortune. I will, in the meantime, tend your
  cattle." The prince did not need to be asked twice, but instantly armed himself with
  helm and harness, buckled spurs on his heels, and a sword by his side, and felt as light
  in his steel armor as a bird in the air. Then vaulting into the saddle, he gave his horse
  the rein, and rode at full speed to he mountain. 
  The princess's suitors had just ceased from their arduous enterprise, in which none had
  won the prize, though each had well played his part, and were now standing and thinking
  that another time fortune might be more favorable, when on a sudden they saw a young
  knight come riding forth from the edge of the forest directly towards the mountain. He was
  clad in steel from head to foot, with shield on arm and sword in belt, and bore himself so
  nimbly in the saddle that it vas a pleasure to behold him. All eyes were instantly
  directed towards the strange knight, each asking another who he might be, for no one had
  seen him before. But they had no long time for asking; for scarcely had he emerged from
  the forest, when, raising himself in the stirrups, and setting spurs to his horse, he
  darted like an arrow straight up the glass mountain. Nevertheless, he did not reach the
  top, but when about half way on the slope, he suddenly turned his charger and rode down
  the hill, so that the sparks flew from his horse's hoofs. He then disappeared in the
  forest as a bird flies. 
  Now, it is easy to imagine, there was a commotion among the assembled multitude, of
  whom there was not one that was not stricken with wonder at the stranger, who, I hardly
  need say it, was no other than the prince. At the same time all were agreed that they had
  never seen a nobler steed or a more gallant rider. It was, moreover, whispered abroad that
  such was also the opinion of the princess herself, and that every night she dreamed of
  nothing but the daring stranger. 
  The time had now arrived when the suitors of the princess should make a second trial.
  As on the first time, she was conducted to the glass mountain, the attempt to climb which
  by the several competitors was attended with a result similar in every respect to what has
  been already related. 
  The prince in the meanwhile was watching his cattle, and unhappy at being unable to
  join in the attempt, when the wild man again appeared before him, who, after listening to
  his complaints, again conducted him to his underground home, where there hung a suit of
  armor formed of the brightest silver, close by which stood a snow-white steed ready
  saddled and fully equipped, pawing the ground with his silver-shod hoofs and champing his
  bit. The prince, following the directions of the wild man, having put on the armor and
  mounted the horse, galloped away to the glass mountain. 
  As before, the youth drew on him the gaze of every one present; he was instantly
  recognized as the knight who had already so distinguished himself; but he allowed them
  little time for observation, for setting spurs to his horse, he rode with an arrow's speed
  up the glassy mountain, when, having nearly reached the summit, he bowed to the princess,
  turned his horse, rapidly rode down again, and again disappeared in the forest. 
  The same series of events took place a third time, except that this time the prince
  received from the wild man a suit of golden armor, cased in which he, on the third day of
  trial, rode to the mountain's summit, bowed his knee before the princess, and from her
  hand received the golden apple. Then casting himself on his horse, he rode at full speed
  down the mountain, and again disappeared in the forest. Now arose an outcry on the
  mountain! The whole assemblage raised a shout of joy; horns and trumpets were sounded, and
  the king caused it to be proclaimed aloud that the stranger knight, in the golden armor,
  had won the prize. 
  All that now remained was to discover the gold-clad knight, for no one knew him. For
  some time hopes were cherished that he would appear at court, but he came not. His absence
  excited the astonishment of all, the princess looked pale and was evidently pining away,
  the king became impatient, and the suitors murmured every day. When no alternative
  appeared, the king commanded a great assemblage to be held at his palace, at which every
  man's son high or low, should be present, that the princess might choose among them. At
  this meeting there was not one who did not readily attend, both for the sake of the
  princess, and in obedience to the king's command, so that there was assembled an
  innumerable body of people. When all were gathered together, the princess issued from the
  royal palace in great state, and with her maidens passed among the whole throng; but
  although she looked in all directions, she did not find not what she sought. Suddenly she
  caught sight of a man who was standing concealed in the crowd. He wore a broad-brimmed
  hat, and was wrapped in a large grey cloak, like those worn by herdsmen, the hood of which
  was drawn up over his head, so that no one could see his face. But the princess instantly
  ran towards him, pulled down his hood, clasped him in her arms and cried: "Here he
  is! here he is!" 
  At this all the people laughed, for they saw that it was the king's herd-boy, and the
  king himself exclaimed: "Gracious heaven support me! What kind of a son-in-law am I
  to have?" 
  But the young man said: "Do not let that trouble you! You will get as good a
  king's son, as you yourself are a king." At the same moment he threw aside his cloak,
  and where were now the laughers, when, in place of the grey herdsman, they saw before them
  a handsome young prince clad in gold from head to foot, and holding in his hand the
  princess's golden apple! All now recognized in him the youth who had ridden up the glass
  mountain. 
  Now, it is easy to imagine, there was joy, the like of which was never known. The
  prince held his beloved in his arms, and told her of his family and all he had undergone.
  The king instantly made preparations for the marriage, to which he invited all the suitors
  and all the people. A banquet was then given such as has never been heard of before or
  after. Thus did the prince gain the king's daughter and half the kingdom; and when the
  feastings had lasted about seven days, the prince took his fair young bride in great state
  to his father's kingdom, where both the king and the queen wept for joy to see him again.
  The prince and his bride ever afterwards lived happily and well. But nothing more was
  heard of the wild man. 
   
  Yule-Tide Stories: A Collection of Scandinavian and North German Popular Tales
  and Traditions. Hrsg. von Benjamin Thorpe. London 1853. (AT 502)