1793
See also: French Revolutionary Wars: Campaigns of 1793On 21 January the revolutionary government executed Louis XVI after a trial. This united all Europe, including Spain, Naples, and the Netherlands against the revolution. France declared war against Britain and the Netherlands on 1 February 1793 and soon afterwards against Spain. In the course of the year 1793 the Empire, the kings of Portugal and Naples and the grand-duke of Tuscany declared war against France. Thus was formed the first coalition.
France introduced a new levy of hundreds of thousands of men, beginning a French policy of using mass conscription to deploy more of its manpower than the other states could, and remaining on the offensive so that these mass armies could commandeer war material from the territory of their enemies. The French government sent Citizen Genet to the United States to encourage them into entering the war on France's side. George Washington, however, demanded he be sent back to France.
Read more about this topic: War Of The First Coalition