Irene’s conversion took place a year before her engagement announcement, but the royal family did not officially announce the news until January 1964. When news leaked out that she was engaged to Prince Carlos Hugo (born 1930), it provoked a Protestant outcry and a constitutional crisis.Although Dutch law did not forbid a Catholic to reign over the Netherlands, Protestant succession was traditional, born out of the 16th-century Eighty Years’ War with Spain and the assassination of William of Orange by a supporter of Philip II of Spain who believed William had betrayed both the Spanish monarch and the Catholic Church.