The border crossing between the British and Russian Zones of Occupation in Northern Germany near the town of Potenitz on the Baltic Sea coast, 1945

In the aftermath of the Second World War in Europe, the victorious Allies divided the defeated Germany between them, with each taking responsibility for their Zone of Occupation. This image shows the crossing point near the town of Potenitz, near Lubeck, on the Baltic Sea Coast.

Initially, relations between the victorious Allies were good. However, they quickly deteriorated with the onset of the Cold War. While the Zones of the Western Allies would be merged in 1949 to create West Germany, the Soviets created East Germany. The frontier between these two new countries, the Inner German Border, stretched 866 miles (1,394km) from the Baltic Sea to Czechoslovakia. It was in force from 1949 until 1990 and was increasingly strengthened by the East Germans with fences, walls and wire, eventually becoming one of the world's most heavily fortified frontiers.