Louis, Dauphin of France

Born 4 September 1729, Louis Ferdinand was the only surviving son of Louis XV and Marie Leszczyńska, which made him heir to the French throne from birth. He carried the title Dauphin - crown prince - for his entire life, a role defined by waiting. He died on 20 December 1765, more than a decade before his father, ensuring he would never rule. What he left behind was a dynasty in three parts: his sons Louis XVI, guillotined in 1792; Louis XVIII, who returned after Napoleon's fall and ruled until 1824; and Charles X, who took the throne until 1830. The father who never reigned fathered the last kings of France.