Complex sentence: The Dauphin died the same day, 8 March 1712 while his younger brother, the Duke of Anjou, was personally treated by his governess, Madame de Ventadour, who forbade any bloodletting.
Split into simpler sentences: The Dauphin died the same day, 8 March 1712. His younger brother, the Duke of Anjou, was personally treated by his governess, Madame de Ventadour, who forbade any bloodletting.