Sweden
On 6 June 1809 the Duke-regent of Sweden was proclaimed King, after Gustav IV Adolf was deposed. The new king Charles XIII accepted the new, liberal Constitution, which was ratified by the Riksdag of the Estates the same day. The new king was in no way likely to interfere with the liberal revolution which had placed him on the throne. Peace was what the exhausted nation now required.
Charles XIII was childless, so in order to secure the succession to the throne, someone had to be he adopted as his heir. Georg Adlersparre, the main orchestrator of the 1809 coup, preferred Frederick VI of Denmark as the new Swedish monarch, but when Frederick refused, Adlersparre looked to Norway. He tried to persuade Christian August, first through the Swedish Baron C. H. Anckarsvärd, and although Christian August did not show up to meet Anckarsvärd personally, he gradually accepted the offer of adoption. His loyalty to his ruler Frederick VI ultimately became a lesser obstacle. The choice of Christian August was supported by Charles XIII as well as three of the estates of the realm; the Clergy, Burghers and Peasants. However, the Nobility was more reluctant due to the influence of so-called Gustavians (Gustavianerna), supporting the deposed King Gustav IV Adolf and his then-underage son. The decision to adopt Charles August became definitive on 15 July 1809. His great popularity in Norway was considered an advantage to the Swedish plans for the acquisition of that country. In addition, he had demonstrated his interest in a rapprochement between the two countries by refraining from invading Sweden during the Finnish War with Russia.
After the Treaty of Fredrikshamn between Sweden and Russia on 17 September 1809 which concluded the Finnish War, Sweden was ready for the inauguration of Charles August. He finally left Norway for Sweden on 7 January 1810. As Crown Prince of Sweden, he changed his name to Charles August (Swedish: Carl August). Honors were lavished upon him on his arrival, he was for example made an honorary member of the Royal Swedish Academy of Sciences on April 18, 1810, and was the first person to enjoy this status in that academy. However, he did not live long enough to make a historical impact in Sweden. He suddenly died on 28 May 1810, when he fell off his horse during a military practice in Kvidinge. His autopsy confirmed that he had died of a stroke, but at the same time rumours went that he had been poisoned by Gustavians. Specifically, the Marshal Count Axel von Fersen was openly accused of having killed Charles August, and was lynched on 20 June 1810 during the funeral procession of Charles August. Charles August was buried in Riddarholmen Church, the burial church of Swedish monarchs.
Read more about this topic: Charles August, Crown Prince Of Sweden