The Inner German border was the frontier between the German Democratic Republic and the Federal Republic of Germany from 1949 to 1990. Not including the similar but physically separate Berlin Wall, the border was 1,393 kilometres long and ran from the Baltic Sea to Czechoslovakia.
It was formally established on 1 July 1945 as the boundary between the Western and Soviet occupation zones of Germany. On the eastern side, it was made one of the world's most heavily fortified frontiers, defined by a continuous line of high metal fences and walls, barbed wire, alarms, anti-vehicle ditches, watchtowers, automatic booby traps and minefields. It was patrolled by 50,000 armed GDR guards. The border was a physical manifestation of Winston Churchill's metaphorical Iron Curtain that separated the Soviet and Western blocs during the Cold War.