Gaston of France, Son of France, Duke of Orléans (Gaston Jean Baptiste; 25 April 1608 – 2 February 1660) was the third son of King Henry IV of France and his wife Marie de Medici. As a son of the king, he was born a "Fils de France". As a young boy he was given the title of Duke of Anjou. Later he had the title Duke of Orléans. As the eldest surviving brother of King Louis XIII, he was known at court as "Monsieur". He was also one of the first princes to use the "style" of "Royal Highness". He is often also referred to as Gaston d'Orléans. His grandson the last Medici Grand Duke of Tuscany was named in his honour. 