Complex sentence: Born to Charles de Rohan, the Prince of Rochefort, and his wife Eléonore Eugénie de Béthisy de Mézières, he was the second child of four and their eldest son.
Split into simpler sentences: Born to Charles de Rohan, the Prince of Rochefort and his wife Eléonore Eugénie de Béthisy de Mézières. He was the second child of four and their eldest son.