Count Frederick of Hesse-Kassel is elected King of Sweden by the Riksdag of the Estates, after his consort Ulrika Eleonora abdicated the throne on 29 February.

Frederick I was King of Sweden from 1720 until his death, having been prince consort of Sweden from 1718 to 1720, and was also Landgrave of Hesse-Kassel from 1730. He ascended the throne following the death of his brother-in-law absolutist Charles XII in the Great Northern War, and the abdication of his wife, Charles's sister and successor Ulrika Eleonora, after she had to relinquish most powers to the Riksdag of the Estates and thus chose to abdicate. His powerless reign and lack of legitimate heirs of his own saw his family's elimination from the line of succession after the parliamentary government dominated by pro-revanchist Hat Party politicians ventured into a war with Russia, which ended in defeat and the Russian tsarina Elizabeth getting Adolf Frederick of Holstein-Gottorp instated following the death of the king. Whilst being the only Swedish monarch called Frederick, he was Frederick I of Hesse-Kassel and thus Frederick I also of Sweden, though other Swedish monarchs with non-repeating names had not been enumerated.

The Swedish Empire or the Great Power era was the period in Swedish history spanning much of the 17th and early 18th centuries during which Sweden became a European great power that exercised territorial control over much of the Baltic region. During this period it also held territories on the North Sea and some overseas colonies, including New Sweden. The beginning of the period is usually taken as the reign of Gustavus Adolphus, who ascended the throne in 1611, and its end as the loss of territories in 1721 following the Great Northern War.

Riksdag of the Estates was the name used for the Estates of Sweden when they were assembled. Until its dissolution in 1866, the institution was the highest authority in Sweden next to the King. It was a Diet made up of the Four Estates, which historically were the lines of division in Swedish society:

• Nobility
• Clergy
• Burghers
• Peasants