Charles I, Marriage of Princess Mary to William of Orange, 1641Mary, daughter of Charles I, married Prince William, the son and heir of Frederick Henry, Prince of Orange and Stadtholder of the United Provinces. Mary was only nine when the marriage took place at Whitehall Palace on 2nd May 1641. The couple’s only child William was born in 1650, the same year that his father succumbed to smallpox. Their son went on to be crowned William III, King of England.