Gaston, Duke of Orléans
On 24 May 1671, the first anniversary of his grandfather Ferdinando II's death, Giovanni Battista Gastone de' Medici was born in Florence to Grand Duke Cosimo III and Marguerite Louise d'Orléans. He derived his baptismal name, Giovanni Battista Gastone, from his maternal grandfather, Gaston, Duke of Orléans. Cosimo and Marguerite Louise frequently quarreled. As a result, four years after his birth, Marguerite Louise returned home to France. Gian Gastone and his siblings were left in the care of their grandmother Vittoria della Rovere.