The Storting is the supreme legislature of Norway, established in 1814 by the Constitution of Norway. It is located in Oslo. The unicameral parliament has 169 members, and is elected every four years based on party-list proportional representation in nineteen plural member constituencies. A member of the Storting is known in Norwegian as a Stortingsrepresentant, literally "Storting representative". The assembly is led by a president and, since 2009 five vice presidents — the presidium.