Since its foundation in 1889, the Social Democratic Party has often been one of the main political forces in Austria. At the start of the First World War it was the strongest party in parliament, and on the ending of that war in 1918 the party leader Karl Renner became chancellor of the First Republic. The party lost power in 1920, but retained a strong base of support in the capital Vienna. A period of rising political violence culminated in the banning of the Social Democratic Party under the Austrofascist dictatorship (1934–38).