MarieThrse Charlotte of France , Madame Royale, was the eldest child of Louis XVI and Marie Antoinette.
MarieThrse was born at the Palace of Versailles onDecember 1778, the first child , and eldest daughter of king Louis XVI of France and queen Marie Antoinette. As the daughter of the king of France, she was a fille de France, and as the eldest daughter of the king, she was styled Madame Royale at birth.
Source: Wikipedia