On 20 August 1961, East German soldiers suddenly began work on a project that would become the most potent symbol of the divisions of the Cold War: the Berlin Wall.

At first, the residents of Berlin were perplexed, but as the wall took shape it cemented the reality of the division. It would stand as an imposing barrier to freedom for the next 28 years.

Watch original footage from the Wall's construction in this British Pathé video, above.