The kings and emperors of many foreign countries were worried by the French Revolution. They did not want revolutions in their own countries. On 27 August 1791, Leopold II of the Holy Roman Empire/Austria, Frederick William II of Prussia, and Louis XVI’s brother-in-law, Charles-Philippe wrote the Declaration of Pillnitz. The Declaration asked for Louis XVI to be set free and the National Assembly to be ended. They promised that they would invade France if their requests were ignored. The Declaration was taken very seriously among the revolutionaries.