Province of Pistoia
Dillon married secondly on 1 March 1967 Prince Charles, brother of Grand Duke Jean of Luxembourg, at the Catholic Church of St. Edward the Confessor in Sutton Park, Surrey, UK. The marriage was the first authorized of a Luxembourgeois prince to a commoner – authorized by Grand Ducal decree issued 16 February 1967. She was styled ""Her Royal Highness" Princess Joan of Luxembourg". Prince Charles died in Imbarcati, Province of Pistoia, Italy, on 26 July 1977. They had two children: