High Quality Content by WIKIPEDIA articles! The development of the inner German border took place in a number of stages between 1945 and the mid-1980s. After its establishment in 1945 as the dividing line between the Western and Soviet occupation zones of Germany, in 1949 the inner German border became the frontier between the Federal Republic of Germany (FRG, West Germany) and the German Democratic Republic (GDR, East Germany). The border remained relatively easy to cross until it was abruptly closed by the GDR in 1952 in response to the large-scale emigration of East Germans to the West. Barbed-wire fences and minefields were installed and draconian restrictions were placed on East German citizens living near the border. Thousands were expelled from their homes, with several thousand more fleeing to the West. From the late 1960s, the border fortifications were greatly strengthened through the installation of new fences, detectors, watchtowers and booby-traps designed to prevent attempts to escape from East Germany. The improved border defences succeeded in reducing the scale of unauthorised emigration to a trickle.