How urban space became a contested space and the idea of the 'master plan' emerged: a panorama of the long turn of the century. Around 1900, it seemed certain: those who wanted to shape the future had to focus on cities. In many places, the chosen means was the international urban planning competition. This process experienced an unprecedented peak between the 1890s and the 1930s. The competition promised nothing less than a 'master plan' - for the layout of transportation routes, building and open spaces, and especially for the social reorganization under the conditions of a time understood as 'modern.' Cosima Götz tells the story of the competitions for Berlin (1908-1910), Canberra (1911/12), Paris (1919/20), and Ankara (1927-1929) as a vivid transnational history of society and ideas over five defining decades. Using a variety of materials - including numerous visual sources - she demonstrates how urban space became a contested space through competitions. And how the attempt to resolve conflicts produced significant ideas and instruments.