The story begins that in England, a good and wise king ruled the country with peace and compassion. However, the good king has fallen ill, and his captain of the guards, Pete, plundered and terrorized the country in the king's name. One day, when Mickey Mouse, Goofy and Pluto, three beggars are trying to get money for some food, dream of "living like a king", Captain Pete's carriage passes, having stolen much food from the people of London, and burying the three heroes in the snow. The hungry Pluto sees a sausage stand out from the carriage and begins to chase, pursuing it into the castle of the king. As Mickey knocks on the door to get his dog back, one of the soldiers opens the door and lets him in, mistaking him for the prince.
Pete lectures the soldier for letting anyone in, pointing out where the real prince: taking his classes with his teacher, Horace Horsecollar. While Horace teaches the prince about trigonometry, the prince looks out the window at the children playing in the snow. The prince, being discovered by his teacher, is mocked by his valet, Donald Duck. The prince plays at provoking Donald, while the teacher is distracted while writing on the blackboard, to the point that Donald inadvertently hits the teacher, resulting in the teacher sending Donald out of the room, returning both to their studies. Then, the Prince hears Pete, who is roughly handling Mickey and Pluto. The prince orders them to be brought to him right away. Pete kicks Mickey through the door, and forces Pluto out of the castle.
While in the king's palace, Mickey inadvertently knocks over many suits of armor, with one of the helmets falling on both his and the approaching Prince's head. Mickey and the Prince both realize that they are entirely alike in appearance. The prince tells the beggar that he is bored with his life: getting up early, studying all day, with every night parties and banquets and then going to bed early. So, when looking at the two in the mirror they realize that they can exchange a costume and take the role of the other, the prince reassures the beggar saying that to rule requires only two things: "That's a splendid idea, I'm glad I thought of it!" and "Guards, seize him!", and if there are any problems, everyone will recognize the true prince with his real ring. Disguised as a beggar, the prince tricks Pete into him leaving the palace. He meets Goofy and Pluto but finds that he can't recognize them at all.
Meanwhile, Mickey is challenged with the prince's studies. While the prince is trying to make a dog play with him by throwing a bone, a pack dogs chase him and the prince flees. Witnessing a couple of soldiers trying to steal a chicken from Clarabelle Cow and her two children Max, & Daisy Duck, the prince orders them to return the chicken but is humiliated. The children explain that for years the soldiers take away their food and belongings in the name of the king. When a carriage containing the village's stolen food goes by, the real prince stops it, showing the real ring. All bow to the Prince as he returns their food. The soldiers attempt to stop the prince, thinking that he is a mere beggar, but fail when he escapes. Meanwhile in the castle, one of the soldiers tells Pete that one of the beggars had the royal ring. Pete is alarmed knowing then that the prince was cast out, and may see the corruption and theft going on outside. The soldier mocks Pete saying that the captain is going to be punished dearly for it, but Pete answers that the prince won't if Mickey becomes the real one.
The beggar, dressed as the prince, is called by Horace and told that he must see his "father", who is now dying. Mickey enters the room of the dying king, but finds that he doesn't have the heart to tell him that he is not the real prince. Before his death, the king tells him he must take his royal birthright and become king. When Mickey knows the true prince must be found as quickly as possible, Pete arrives behind him, and orders Mickey to be crowned king at his orders or he will kill Pluto.
Meanwhile, the true prince hears the bells announcing the death of his beloved father. Realizing that he should be king, the Prince decides to return immediately to the palace. Pete captures the Prince and detains him with Donald, while the coronation begins. The beggar does not want to be king, but sees that behind the curtain Pete is strangling Pluto. As the prince orders the guard to let them leave, the guard refuses to obey. Goofy disguises himself as an executioner, and after accidentally knocking out the guard, he attempts to figure out which key opens the cell while the other soldiers arrive. When he sees them, Donald screams and finds the key for the cell, and runs with the other two to the coronation chamber.
While struggling not to be crowned, the prince stops the archbishop, and has the guards arrest Pete, but gets exposed as an impostor. The Prince arrives and fights Pete as many other soldiers are defeated by Goofy's clumsiness and Donald's cowardice. Finally, the Prince cuts Pete's trousers loose, revealing Pete's ruffled underpants. Pete attempts to escape from a large chandelier that has fallen and entangled some soldiers, but has been tripped up by Mickey and the Prince, and falls down to the ground. With his trousers down and his ruffled underwear fully displayed, Captain Pete becomes entangled with the soldiers in the fallen chandelier and falls out of a window to his unknown fate.
Mickey and the Prince then cheer because of their successful collaboration in defeating Captain Pete. The archbishop is confused and does not know who to crown, until Pluto recognizes the beggar. The real Prince is crowned King of England, and with Mickey and Goofy at his side, rules for many years with justice and compassion for all.Wayne Allwine – Mickey Mouse and The Prince
Arthur Burghardt – Captain Pete
Tony Anselmo – Donald Duck
Bill Farmer – Goofy, Pluto, Horace Horsecollar and Weasel #1
Elvia Allman – Clarabelle Cow
Charlie Adler – Weasel #2, Pig Driver, Peasant and Man in Street
Frank Welker – The King and Archbishop
Trevor Eyster – Kid #1
Rocky Krakoff – Kid #2
Roy Dotrice – The Narrator