Riksdag Riksdag of the Estates, by tradition thought to have first assembled in Arboga in 1435, and in 1866 following reforms of the 1809 Instrument of Government that body was transformed into a bicameral legislature with an upper chamber () and a lower chamber (). The most recent general election was held on 9 September 2018. The Swedish word "riksdag", in definite form "riksdagen", is a general term for "parliament" or "assembly", but it is typically only used for Sweden's legislature and certain related institutions. In addition to Sweden's parliament, it is also used for the Parliament of Finland and the
Riksdag of the Estates provinces to the Russian Empire. Comprising much of present-day Finland, these became a Grand Duchy under the Emperor, but the political institutions were kept practically intact. The Finnish estates assembled in 1809 at Porvoo to confirm the change in their allegiance. This Diet of Finland followed the forms of the Swedish Riksdag, being the legislative body of the new autonomous region. However, during the reigns of Alexander I and Nicholas I it was not assembled and no new legislation was enacted. The diet was next assembled by tsar Alexander II in 1863, due to the need to modernize the laws.