Gustav IV Adolf of Sweden

On 21 February 1808, Russia invaded Finland, which consisted of provinces of Sweden, on the pretext of compelling Sweden to join Napoleon's Continental System. Denmark likewise declared war on Sweden. In just few months after, almost all of Finland was lost to Russia. As a result of the war, on 17 September 1809, in the Treaty of Hamina, Sweden surrendered the eastern third of Sweden to Russia. The autonomous Grand Principality of Finland within Imperial Russia was established.

Gustav Adolf's inept and erratic leadership in diplomacy and war precipitated his deposition through a conspiracy of army officers.

On 7 March 1809, lieutenant-colonel Georg Adlersparre, commander of a part of the so-called western army stationed in Värmland, triggered the revolution by raising the flag of rebellion in Karlstad and starting to march upon Stockholm. To prevent the King from joining loyal troops in Scania, on 13 March 1809 seven of the conspirators led by Carl Johan Adlercreutz broke into the royal apartments in the palace, seized the king, and imprisoned him and his family in Gripsholm castle; the king's uncle, Duke Charles (Karl), was thereupon persuaded to accept the leadership of a provisional government, which was proclaimed the same day; and a diet, hastily summoned, solemnly approved of the revolution. Read Less