Riksdag Swedish king Gustav I Vasa to include representatives from all the four social estates: the nobility, the clergy, the burghers (property-owning commoners in the towns such as merchants etc.), and the yeomanry (freehold farmers). This form of "Ständestaat" representation lasted until 1865, when representation by estate was abolished and the modern bicameral parliament established. Effectively, however, it did not become a parliament in the modern sense until parliamentary principles were established in the political system in Sweden, in 1917. On 22 June 1866, the Riksdag decided to reconstitute itself as a bicameral legislature, consisting of "Första kammaren" or the First
Riksdag members of the Riksdag are elected in the general elections held every four years. All Swedish citizens who turn 18 years old no later than on the day of the election are eligible to vote in and stand for elections. A minimum of 4% of the national vote is required for a party to enter the Riksdag, alternatively 12% or more within a constituency. Substitutes for each deputy are elected at the same time as each election, so by-elections are rare. In the event of a snap election, the newly elected members merely serve the remainder of the four-year term.