Constanza married John "Of Gaunt" Prince Of ENGLAND, [DUKE OF LANCASTER] in Sep 1371 in , Rochefort-sur-Mer, Charente-Maritime, France. John was born in Mar 1340 in Abbaye de St Bavon, Ghent, Flandre-Orientale, Belgium; died on 3 Feb 1398/99 in Leicester Castle, Leicester, Leicestershire, England; was buried on 15 Mar 1398/99 in St Paul's Cathedral, London, Middlesex, England. [Group Sheet] [Family Chart]