Prince Prospero’s name is ironic because he dies at the end.
It is not hard to determine the significance of Prince Prospero’s name. “Prospero” sounds like “prosper.” Prince Prospero tries to prosper at the expense of his people.
But the Prince Prospero was happy and dauntless and sagacious. When his dominions were half depopulated, he summoned to his presence a thousand hale and light-hearted friends from among the knights and dames of his court, and with these retired to the deep seclusion of one of his castellated abbeys.
As the prince, Prospero was responsible for his kingdom. As the red death decimated his people, he thought of no one but himself. Prospero could have tried to help his people, but instead he helped himself. He took a thousand of his closest friends, courtiers and nobles, and locked himself and them away in a castle.
Seeking to prosper on his own, at their expense, Prince Prospero held a ball about six months into his hiding stint.
It was toward the close of the fifth or sixth month of his seclusion, and while the pestilence raged most furiously abroad, that the Prince Prospero entertained his thousand friends at a masked ball of the most unusual magnificence.
Prince Prospero’s ball has an uninvited guest. The people are celebrating and having fun—prospering—but it is temporary. Prospero is only delaying the inevitable. He dies, and so do all of his guests. You can’t escape death just by being rich.
Propsero’s ironic name sends a message to Poe’s readers. People who are selfish and use their wealth to hurt others, or who steal from others, will eventually get what is coming to them. Like Shakespeare’s play The Tempest, which has a main character named Prospero, this story is about revenge. In the end, the dead got revenge on the man who abandoned them.