Prince, Dauphin. Louis Joseph Xavier François de France, son of King Louis XVI of France and his wife Queen Marie Antoinette, was born at the Palace of Versailles. As the heir apparent to the throne, he was the Dauphin of France. Louis had three siblings: Marie Thérèse, Louis Charles, and Sophie. In 1784 and 1786, he developed a series of fevers. However, these worsened in 1788 and there was rapid progression of his illness. The following year, the young Dauphin of France died of tuberculosis at the Château de Meudon. Louis Joseph was interred at the Royal Basilica of Saint Denis. It has been speculated that the grief of the king and queen over the death of their son may have been contributory factors in the events which led to the French Revolution, the beginning of which is dated about two weeks after his death. His younger brother Louis Charles, Duke of Normandy, succeeded him as Dauphin, and became Louis XVII, dying in prison at the age of ten. Dauphin County, Pennsylvania is named after Louis Joseph de France, a gesture of thanks from the Pennsylvania Legislature for France's role in the American Revolutionary War.