Three Bogatyr (or Three Brave Knights)

Kyiv was in turmoil. The Prince of Kiev sat on the throne. His horse, Julius, paced the hall nervously. "Well, that's it, our stability is over!" Julius sighed. "The Prince is ill, there's a hole in the treasury, and our enemies are probably already rewriting the cards: where can we grab what from here..." "Quiet," Antip hissed. "We can't let rumors spread." The heroes burst noisily into the hall: Ilya Muromets, Dobrynya Nikitich, and Alyosha Popovich. The Prince raised his head and smiled faintly.
"My friends, support of the Russian land. Hear my will. I have decided that my niece Zabava will be heir to the throne. She is now in Constantinople, studying and seeing the world."
“Zabava?” Alyosha was surprised. “So she’s there alone?” “Yes,” the prince nodded. “Go to Constantinople. Find Zabava and bring her here. But most importantly, keep everything secret. As long as I’m alive and well in the eyes of the people, as long as Zabava doesn’t take her place at my side, not a word about the illness…” Zabava stood by the window of the imperial palace and looked out at the bustling city. Meanwhile, a new accountant, Yelisey, had arrived at the palace. Meanwhile, Zabava, tired of being alone, decided to take a stroll through the palace garden. She descended the marble staircase, unaware that a collision—literally—was waiting for her around the corner. Yelisey, engrossed in studying the palace map, abruptly turned the corner and bumped into someone. A folder of documents scattered across the floor. “Oh, forgive me!” he exclaimed, looking up. Before him stood a girl of amazing beauty, in a rich dress, with a pensive look.
"It's okay," Zabava replied softly, helping him gather up the papers. "You must be the new accountant?"

• Y-yes... Elisha, -
  And somewhere on the way to Constantinople, three heroes and the restless horse Julius were already racing to protect the heir to the throne from the intrigues of the Basileus and return her to her native land.