Faithful John, also known as Trusty John, Faithful John, Faithful Johannes, or John the True.
This is the Brothers Grimm version of the story and translated into English by Margarate Hunt.
The approximate narration time is 22 minutes
There was once on a time an old king who was ill, and thought to himself, "I am lying on what must be my death-bed." Then said he, " Tell Faithful John to come to me." Faithful John was his favourite servant, and was so called, because he had for his whole life long been so true to him. When therefore he came beside the bed, the King said to him, "Most faithful John, I feel my end approaching, and have no anxiety except about my son. He is still of tender age, and cannot always know how to guide himself. If thou dost not promise me to teach him everything that he ought to know, and to be his foster-father, I cannot close my eyes in peace." Then answered Faithful John, "I will not forsake him, and will serve him with fidelity, even if it should cost me my life." On this, the old King said, "Now I die in comfort and peace." Then he added, "After my death, thou shalt show him the whole castle: all the chambers, halls, and vaults, and all the treasures which lie therein, but the last chamber in the long gallery, in which is the picture of the princess of the Golden Dwelling, shalt thou not show. If he sees that picture, he will fall violently in love with her, and will drop down in a swoon, and go through great danger for her sake, therefore thou must preserve him from that." And when Faithful John had once more given his promise to the old King about this, the King said no more, but laid his head on his pillow, and died.
When the old King had been carried to his grave, Faithful John told the young King all that he had promised his father on his deathbed, and said, "This will I assuredly perform, and will be faithful to thee as I have been faithful to him, even if it should cost me my life." When the mourning was over, Faithful John said to him, "It is now time that thou shouldst see thine inheritance. I will show thee thy father's palace." Then he took him about everywhere, up and down, and let him see all the riches, and the magnificent apartments, only there was one room which he did not open, that in which hung the dangerous picture. The picture was, however, so placed that when the door was opened you looked straight on it, and it was so admirably painted that it seemed to breathe and live, and there was nothing more charming or more beautiful in the whole world. The young King, however, plainly remarked that Faithful John always walked past this one door, and said, "Why dost thou never open this one for me?" - "There is something within it," he replied, "which would terrify thee." But the King answered, "I have seen all the palace, and I will know what is in this room also," and he went and tried to break open the door by force. Then Faithful John held him back and said, "I promised thy father before his death that thou shouldst not see that which is in this chamber, it might bring the greatest misfortune on thee and on me." - "Ah, no," replied the young King, "if I do not go in, it will be my certain destruction. I should have no rest day or night until I had seen it with my own eyes. I shall not leave the place now until thou hast unlocked the door."
Then Faithful John saw that there was no help for it now, and with a heavy heart and many sighs, sought out the key from the great bunch. When he had opened the door, he went in first, and thought by standing before him he could hide the portrait so that the King should not see it in front of him, but what availed that? The King stood on tip-toe and saw it over his shoulder. And when he saw the portrait of the maiden, which was so magnificent and shone with gold and precious stones, he fell fainting to the ground. Faithful John took him up, carried him to his bed, and sorrowfully thought, "The misfortune has befallen us, Lord God, what will be the end of it?" Then he strengthened him with wine, until he came to himself again. The first words the King said were, "Ah, the beautiful portrait! whose it it?" - "That is the princess of the Golden Dwelling," answered Faithful John. Then the King continued, "My love for her is so great, that if all the leaves on all the trees were tongues, they could not declare it. I will give my life to win her. Thou art my most Faithful John, thou must help me."
The faithful servant considered within himself for a long time how to set about the matter, for it was difficult even to obtain a sight of the King's daughter. At length he thought of a way, and said to the King, "Everything which she has about her is of gold - tables, chairs, dishes, glasses, bowls, and household furniture. Among thy treasures are five tons of gold; let one of the goldsmiths of the Kingdom work these up into all manner of vessels and utensils, into all kinds of birds, wild beasts and strange animals, such as may please her, and we will go there with them and try our luck." The King ordered all the goldsmiths to be brought to him, and they had to work night and day until at last the most splendid things were prepared. When everything was stowed on board a ship, Faithful John put on the dress of a merchant, and the King was forced to do the same in order to make himself quite unrecognizable. Then they sailed across the sea, and sailed on until they came to the town wherein dwelt the princess of the Golden Dwelling.
KHM: Kinder- und Hausmärchen (Children's and Household Tales)