By issue of the Trennungsgesetz in 1921, Vienna became an autonomous federal state and corporate town on 1st January 1922. The district council, which is also the state parliament, consists of 100 members and is elected for five years. The city senate, made up of 13 people (1995) is also the state government; the mayor is the state governor and the magistrate is the department of the state government.
The city senate consists of the mayor, 2 deputy mayors and the city councillors, and is elected by the district council for five years.
The magistrate district office with its elected district superintendents and representatives are decentralised administrative agencies. Vienna has 11 mandates in the Federal Assembly and 41 in the National Assembly.
Until 1918, Viennese politics were shaped by the Christian Social Party, in particular long-term mayor Karl Lueger. Vienna is today considered the centre of Social Democracy in Austria. During the period of the First Republic (1918-1934), the Vienna Social Democrats undertook many overdue social reforms, improving the quality of life for hundreds of thousands of workers in the city. At that time, Vienna's municipal policy was admired by Socialists throughout Europe, who therefore referred to the city as "Red Vienna" (Rotes Wien). Since the end of the First World War, the city has been governed by the Social Democratic Party with absolute majorities in the city parliament. Only between 1934 and 1945, when the Social Democratic Party was illegal, mayors were appointed by the austro-fascist and later by the Nazi authorities. Current mayor of Vienna is Michael Häupl. The Social Democrats currently hold 55% of the seats with a 49% share of the vote. An example of the city’s many social democratic policies is its low-cost residential estates called Gemeindebauten.
Ever since Vienna obtained federal state (Bundesland) status of its own in 1921, the mayor has also had the role of the state governor (Landeshauptmann). The Rathaus accommodates the offices of the mayor and the state government (Landesregierung). The city is administered by a multitude of departments (Magistratsabteilungen).