A new Act of Succession is adopted by the Riksdag of the Estates and Jean Baptiste Bernadotte becomes heir to the Swedish throne.

The 1810 Act of Succession (Swedish: 1810 års successionsordning, lit. 'the 1810 order of succession') is one of four Fundamental Laws of the Realm (rikets grundlagar) and thus forms part of the Swedish Constitution. The Act regulates the line of succession to the Swedish throne and the conditions which eligible members of the Swedish Royal Family must abide by in order to remain in it.

It was jointly adopted by the Riksdag of the Estates, convened in Örebro on 26 September 1810, and Charles XIII, as a logical consequence following the election on 21 August of Jean Baptiste Bernadotte as Crown Prince.

The actual contents of the Act, save the solemn preamble, has been thoroughly rewritten over the years: the most notable change occurred in 1980 when the core principle of agnatic primogeniture (male succession only) was changed in favor of absolute primogeniture (eldest child regardless of sex).