This is a story of how a lot of Walt Disney Animations movie are somehow connected. This is a story of tragedy, persistence, survival, and may contain spoilers:
It was sometime around the 1850s. The King and Queen of Arendell headed for Rapunzel's wedding not only because of diplomatic reasons, but also because the King of Arendell was the Brother of the Queen of Corona. Their grandmother was Cinderella, who, in a society where the first-born is the heir, was descended to Aurora's youngest child.
However, As the Ship sunk on the way to Rapunzel's wedding, the King and Queen grabbed for dear life a piece of floating wood. They suddenly were rescued by a ship of pirates. They were initially happy to be alive. But then they realized that it was a slave ship, which was morally reprehensible.
They were held prisoner as they tried to escape, but they couldn't. They befriended the slaves, as the slaves were sold in the Americas. However, the King and Queen weren't sold, as they were going to be sold for ransom. Many years passed, mustaches grew bigger, white hair was dyed to red, which was possible since ancient times through a substance called mehndi, somehow eye colors switched, and the emancipation proclamation passed.
Meanwhile, the duke of weselton, who was the youngest grandson of Belle and the beast, left his near adult son to profit from Arendell's economy. The son, disgusted by his father, left politics, and found another interest: biology. The Sunken ship was also explored by Ariel during this time.
Ariel would soon after marry Eric, a descendant of Snow White, whose step mother was none other than mother Gothel, who previously was the Evil Queen about 300 years before. After disguising herself as an old women in order to feed Snow White the apple, she had sacrificed her youth. She lost her magic, which was dependent on the stuff in her castle. When she fell from the cliff, she barely survived. Using the remaining of her powers, she healed enough to search for the flower she had heard legends about since childhood. She found the flower, and the rest of the story is shown in Tangled.
Many years later, the pirate slavers eventually rejected their former ways. They were looking for a profitable activity. They made peace with their hostages, and set the slaves free in Africa. With their new ship, they started to sail back to Arendell to return the king and queen back to their home, a noble pursuit. After many years of surviving, the former king and queen of Arendell were finally happy that they were finally free. They bore a child, and for some reason, decided to take a picture.
The ship crashed. By then, it was the 1880s, and they were near Africa. This brought up many bad memories, they were too shocked to do anything. The captain noticed they were drowning, and in order to redeem himself of his unforgivable crimes, he sacrificed himself to save two of the people whose normal life he stole. They made it to a nearby island and wept before they built a tree house for shelter. They went out in search for food, but they were eaten by a leopard.
Their young son Tarzan was raised by the Apes, until the Son of the Duke of Weselton, known as Professor Porter, came to the island with his daughter Jane, and met Tarzan, whose sister was the reason he hated his father and became a Biologist.
Also, Hiro Hamada from big hero 6 is distantly related to Gogo Tomago, who are both descended to Mulan, whose decendents merged with the japanese during the Sino-Japanese War. Wasabi is the great, great, great grandson of Tiana and Naveen from the princess and the frog. Honey Lemon is the great, great, great grandchild of Tarzan and Jane, as her grandparents left the island, and She inherited the love of Science from Professor Porter. Finally, Fred's ancestry includes Ariel (therefore Snow White), Cinderella, Aurora, and Rupanzel, explaining why he's stupidly rich.
San Fransokyo is where people from different cultures came together, and is also home to the arcade from wreck it Ralph.
Jim from Treasure planet is descended to every disney character that belongs to this connected universe.