Potsdam Alliance Convention of 1805

a convention between Russia and Prussia signed in Potsdam on October 22 (November 3) by Prince A. A. Chartoryiskii for Prussia and Baron K. A. von Hardenberg, minister of state, for Prussia; on the same day, the convention was joined by Austria, which was defeated by France at Ulm.

By the terms of the convention, Prussia would act as mediator for Russia and Austria with regard to France in order to persuade Napoleon I to give up a significant portion of the territories he had conquered in Germany and Italy. Should the mediation fail, Prussia pledged to join the coalition at once and to send an army of 180,000 men or more against France. At the same time, Prussia was promised English subsidies, Russian supplies, and certain territorial gains at the end of the war. In spite of the convention, Frederick William III strove to avoid war with France. After Napoleon’s victory in the battle of Austerlitz of Nov. 20 (Dec. 2), 1805, Frederick William III virtually repudiated the Potsdam Alliance Convention and concluded the Treaty of Schönbrunn of 1805 with France.