During his childhood, his aged great-grandmother, Philippa of Gelderland, died in 1547, leaving also her inheritance to the young Charles.

[2] According to Julio Alvarotto, envoy of Ercole II d'Este, Duke of Ferrara, Charles paid for a masque involving pageant ships with sails of silver cloth, designed by Bartolomeo Campi, at the wedding of Mary, Queen of Scots, and Francis, Dauphin of France, on 24 April 1558.

The reign of Charles III is regarded as a great age of peace and prosperity for Lorraine.

He pursued a policy of neutrality between France and The Holy Roman Empire, as well as during the French Wars of Religion.

He married Claude of Valois, princess of France, daughter of king Henry II and Catherine de' Medici.