This section is from the book "Myths And Folk-Tales Of The Russians, Western Slavs, And Magyars", by Jeremiah Curtin. Also available from Amazon: Myths and Folk-Tales of the Russians, Western Slavs, and the Magyars.
ONCE there was a king, and he had three sons. The king rejoiced in his three sons, and resolved to have them instructed in a befitting manner, so that he might leave good heirs to the kingdom. Therefore he sent his sons to school, where they got on well enough for a time, till at length they turned their backs on the school, went home, all three, and knew their studies no more.
The king grew fiercely angry at this, forbade his sons to stand before his face, and betook himself to live in the chamber of his palace next the rising sun, where he sat continually at the window and looked towards the east as if waiting for something; and with one eye he wept unceasingly, while with the other he laughed.
After the three princes had grown up to a good age, they agreed among themselves to inquire of the king why he was always sitting in the chamber next the rising sun, and why one of his eyes was always crying, while the other was always laughing. First the eldest son went in and put the question, saying, "My father the king, I have come to ask why one of thy eyes is always crying and the other always laughing, while thou art looking continually towards the east".
The king measured his son with his eyes from head to foot, said not a word, but took a sword which hung at the window and hurled it at him with such force that it sank into the door up to the hilt. The prince sprang through the door, thus escaping the blow aimed at him. When he came out his brothers asked what success he had had. He answered: "Try yourselves; then ye will know." The second brother tried, with the same result as the first. At last the youngest, who was called Mirko, went in and declared the cause of his coming. The king answered him not, but seized the sword in still greater anger, and hurled it at him so that it entered the stone wall up to the hilt. Mirko did not spring aside, but went to the sword, drew it out of the stone wall, took it to the king, his father, and placed it before him on the table.
Seeing this, the king opened his mouth and said to Mirko: "I see now, my son, that thou knowest somewhat better than thy two brothers what honor is; to thee then will I give answer. My one eye weeps unceasingly for sadness at your insignificance, not being fit to rule; but my other eye laughs because in the time of my youth I had a trusty comrade, the Hero of the Plain, who battled by my side, and he promised that if he should overpower his enemies he would come to dwell with me, that we might pass the days of our old age together. For this reason I sit ever by the window next the rising sun, because I await his coming; but every day there rise up against the Hero of the Plain, who dwells in the silken meadow, as many enemies as there are grass-blades on the field. Every day he unaided cuts them down; and until all his enemies have disappeared, he will not be able to come to me".
With that Mirko left his father's chamber, came out to his brothers, and told them the king's speech. They counselled together again, and agreed to ask leave of the king to try their fortune. First the eldest son went to his father and made known his wish. The king consented, and the eldest brother went to the royal stables where he chose a good steed, which he saddled next day, and set out on his journey. After he had been absent a whole year, behold he rides home, bearing on his shoulders the top of the copper bridge, which he threw down before the palace. He went in then, stood before the face of the king, and told him where he had been and what he had brought back.
The king heard his son's discourse to the end, and said: "Oh, my son, when I was of thy age the road to the copper bridge was a two hours' ride for me. Thou art a soft hero. Thou wilt never make vitriol. Go thy way".
With that, the eldest son left his father's chamber. After him the second brother went in, and asked leave of the king to try his fortune. Having received it, he went also to the stables and chose a good steed, which he saddled, mounted, and went his way. At the end of a year he came home, bringing the top of the silver bridge, which he threw down in front of the palace; then he stood before the king, his father, and told him where he had been and what he had brought back.
"Oh," said the king, "when I was of thy age that was only a three hours' ride for me. Thou too art a soft hero; nothing at all will come of thee." With that he dismissed the second son.
At last Mirko appeared; he also asked to try his fortune. The king consented, and Mirko went to the stables to choose a steed. Finding nothing to his mind, he went out to the royal stud and examined it carefully, but could not decide which steed to take. Just then an old witch chanced to be passing that way, and asked what he wanted. Mirko told her. "Oh, my master," said she, "thou wilt not find a horse to thy wish here, but I will tell thee how to find one. Go to the king, thy father, and ask him for the horn with which in his youth he called together his golden-haired steeds. Sound this horn and the steeds will appear at once. Choose not among the golden-haired ones; but last of all will come a shaggy-coated, crooked-legged old mare, - thou wilt know her by this, that when she strikes the pillars with her tail the whole palace will tremble from the blow. Choose her; try thy fortune with her".
Mirko took the old witch's advice, went straightway to the king and said: "My father, I have come that thou mayest give me the horn with which in thy youth thou wert wont to call together thy golden-haired steeds".
The king asked: "Who told thee of this horn? '
"No man," answered Mirko.
"Well, my dear son, if no man told thee, thou art wise; but if some man told thee, he does not wish thee harm. I will tell thee where to find the horn; the rust has eaten it up, perhaps, by this time. In the seventh cellar it is enclosed in the wall; look for it, take it out, and make use of it if thou art able".