What was the Russo-Prussian Treaty of Kalisz?
The Russo-Prussian Treaty of Kalisz was a formal alliance concluded on February 28, 1813, between Tsar Alexander I of Russia and King Frederick William III of Prussia. Negotiated in part by the Prussian statesman Karl, Reichsfreiherr vom und zum Stein, the treaty served as the official signal for Prussiaâs entry into the War of Liberation against Napoleon.12
Under the terms of the agreement, Frederick William III committed to not making peace with France until the kingdom of Prussia had been restored to an area and population equivalent to its pre-Treaties of Tilsit status, though Prussia agreed to renounce most of the territory it had acquired during the second and third partitions of Poland. This alliance was a pivotal development in the Napoleonic Wars, as it solidified the coalition against French hegemony and led to a formal declaration of war by Prussia on March 16, 1813.1