Since I'm not familiar with 'the king's palace story', it's hard to say for sure. But typically in a story set in a king's palace, the king would be a central figure. He might be accompanied by his trusted knights or generals. There could also be a female lead, like a princess or a powerful sorceress who has an influence in the palace. And of course, the servants who keep the palace running could also be important characters.
I don't know this story specifically, but it could have the king as a main character. There might also be his queen, princes or princesses, and perhaps important advisors or nobles in the palace.
Since I don't know the exact 'king of the palace story', it's hard to say for sure. But most likely, the king himself is a main character. There could also be his queen, if there is one in the story. And perhaps his advisers, servants, and noblemen who play important roles in the events that take place in the palace.
The obvious main character would be the undead king himself. He is likely to be at the center of the story. There could be other important characters such as his advisers, if he has any. They might be undead as well or some other dark entities. And there may be characters from outside the palace who try to enter the palace of darkness for various reasons, like treasure hunters or adventurers, and they could also be main characters as their actions might drive the plot forward.
Obviously, the undead king is one of the main characters. He is central to the story as the title suggests.
Since I haven't read it, I can't say for sure. But likely the king of death is one of the main characters.
Since I don't know the exact 'the king's palace story', it could be a story centered around the king in his palace. It may involve his rule, his relationships with his courtiers, and the daily life and politics within the palace. Maybe there are tales of grand feasts, important decisions, and intrigues among the palace inhabitants.
In 'the king's bride story', the king and his bride are central. But we can't forget about other possible characters. The king's guards might be important as they protect the king and the bride. If the story is set in a larger kingdom, there could be regional lords who have different reactions to the king's new bride. There could also be a priest or religious figure if the marriage has a religious ceremony. And the story might introduce a character like a jester or a minstrel who provides some comic relief or a different view on the events related to the king and his bride.
In a possible 'the king's wardrobe story', the king would be the central character. Then there could be his royal tailor, who is in charge of creating and maintaining the clothes in the wardrobe. Additionally, there might be a curious courtier who is always interested in the king's fashion choices and tries to get a peek into the wardrobe. There could also be a thief who attempts to steal from the wardrobe, making him an important character in the story.
As I don't know the specific 'little king's story', it could be the little king himself as the main character. Maybe there are his loyal servants or advisers too.
Most likely, the king is one of the main characters since it's his drum. There could also be a character who is either in charge of the drum, like a drummer or a keeper. And perhaps a character who gets into trouble regarding the drum, like a curious commoner or a mischievous courtier.
The main characters are King George VI and Lionel Logue.