“Vienna is full”, caricature of the housing crisis, from Der Morgen of 9 September 1918

By 1910 Vienna had grown to become an international metropolis with around 2.1 million inhabitants and worldwide cultural and scientific significance.

Vienna was bigger than ever before during the First World War and never as big later. There were no censuses held during the war, so there are no secured statistics to analyse, but numerous indications show that the population must have risen to more than 2.4 millions.