The Treaty of Chaumont was a series of separately-signed but identically-worded agreements in 1814 between the Austrian Empire, the Kingdom of Prussia, the Russian Empire and the United Kingdom. They formed the Holy Alliance. They were dated 1 March 1814, although the actual signings took place on 9 or 19 March. The treaty was intended to draw the powers of the Sixth Coalition into a closer alliance in the event that France rejected the peace terms they had recently offered. Each agreed to put 150,000 soldiers in the field against France and to guarantee the European peace (once obtained) against French aggression for twenty years.
Following discussions in late February 1814, representatives of Austria, Prussia, Russia, and Great Britain reconvened a meeting at Chaumont, Haute-Marne on 1 March 1814. The resulting Treaty of Chaumont was signed on 9 or 19 March 1814, (although dated 1 March), by Emperor Alexander I, Emperor Francis II (with Metternich), King Frederick William III, and British Foreign Secretary Viscount Castlereagh. The treaty called for Napoleon to give up all conquests, thus reverting France to its pre-revolutionary borders, in exchange for a cease-fire. If Napoleon rejected the treaty, the Allies pledged to continue the war. The following day, Napoleon rejected the treaty, ending his last chance of a negotiated settlement.
The decisions were again ratified and put into effect by the Congress of Vienna of 1814-1815. The terms were largely written by Lord Castlereagh, the British foreign minister, who offered cash subsidies to keep the other armies in the field against Napoleon. Key terms included the establishment of a confederated Germany, the division into independent states, the restoration of the Bourbon kings of Spain, and the enlargement of the Netherlands to include what in 1830 became modern Belgium. The treaty became the cornerstone of the European Alliance which formed the balance of power for decades.