1792 Imperial election 21 at Varennes-en-Argonne. On August 27, Leopold and Frederick William II of Prussia, king of Prussia, issued the Declaration of Pillnitz, calling for the release of Louis and Marie Antoinette and promising that, if his safety was threatened, and with the support of the other monarchs of Europe, they would go to war to restore him. The National Assembly interpreted the declaration as a declaration of war against the revolutionary government. On April 20, 1792, it declared war on Leopold's son Francis II, Holy Roman Emperor, his successor as king of Hungary, king of Croatia and king of Bohemia. The
Substantive title queens regnant were usually, but not automatically, elevated to the wife's ruling status, sometimes as co-King and sometimes as King consort (e.g. John III of Navarre, Philip II of Spain, Francis II of France, Henry, Lord Darnley ("later" Duke of Rothesay, etc.), William III, Pedro III of Portugal, Ferdinand II of Portugal, Francis II of Spain), etc. Substantive title A substantive title is a title of nobility or royalty acquired either by individual grant or inheritance. It is to be distinguished from a title shared among cadets, borne as a courtesy title by a peer's relatives, or acquired through marriage.