Who is Louis-Charles from Revolution and what is their importance?

Louis-Charles, son of Louis XVI and Marie-Antoinette, is the dauphin of France, the next in line for the throne. When the revolution begins, the rebels imprison the royal family and later execute the king and queen for treason, leaving Louis-Charles as a danger to the rebellion because he is the next in line as king. In response to this threat, Robespierre imprisons Louis-Charles in the Temple, a large tower in Paris, where he is left alone to fall prey to madness and starvation.