Berlin > Greater Berlin
Industrialisation created a huge number of new jobs in factories around Berlin, triggering a dramatic rise in the population. After 1850, the population of the region doubled approximately every 25 years. However, Berlin's leap to a cohesive metropolis occurred only after Greater Berlin was founded in 1920. Seven neighbouring towns (Spandau, Köpenick, Charlottenburg, Wilmersdorf, Schöneberg, Neukölln and Lichtenberg), as well as 59 rural communities and 27 estate districts, were incorporated under a single administration. On 25 April 1920, the Prussian State Assembly narrowly voted to approve the merger by 164 to 148. Prosperous towns such as Charlottenburg and Wilmersdorf feared for their economies, but the merger was definitely good for housing construction. Vast land reserves were tapped for building projects, and the new districts gave Berlin several independent centres with their own working infrastructures.