The Treaty of Saint Petersburg was signed in Saint Petersburg on April 5, 1812, between Sweden and the Russian Empire. The treaty established an alliance between Russia and Sweden against the French Empire of Napoleon. The alliance was invoked during the War of the Sixth Coalition.
See also Napoleonic Wars
References
Further reading Will Durant, Ariel Durant (1975) The Age of Napoleon (Simon and Schuster) Ulf Sundberg (1997) Svenska freder och stillestånd 1249-1814 (Hjalmarson & Högberg)