After giving safe harbour to thousands of people fleeing Nazi persecution in Europe, the British government decided that some of them could be a threat – and locked all of them up. For many, it was a betrayal on the part of their supposed liberators

Hilde Marchant, star reporter for the Daily Express, heard the story from a sailor. At first she didn’t believe it. Two nights earlier, the sailor explained, he had been standing on the deck of a ship loaded with British nationals headed to England, and watched as a confetti of parachutes drifted into Rotterdam harbour. Dangling from each silhouetted disc, the sailor insisted, were German soldiers dressed, not in Nazi uniforms, but skirts and blouses. Each carried a submachine gun. When the disguised paratroopers landed, another witness claimed, men and women working as cleaners and servants emerged from basements and back doors wearing German uniforms. These traitorous individuals, the witness said, had come to Holland claiming to be refugees from Nazi oppression, sleeper agents posing as asylum seekers.

On 13 May 1940, three days after the invasion of the Netherlands began, the Daily Express published Marchant’s story under the headline “Germans dropped women parachutists as decoys”. Peppered throughout Marchant’s story was the term “fifth columnist” – one that, a short time before, would have been unrecognisable to most readers. Marchant was one of the first people to adopt the phrase, coined during the 1936 Spanish civil war as shorthand for traitors poised to support an enemy invasion from within. British newspapers had begun to refer to fifth columnists after the German invasion of Norway in early April 1940, when reports circulated that spies had been installed in the country to aid the German invasion. By the time Marchant’s story ran, there wasn’t a reader in Britain unaware of the term, or the notion that a similar network of duplicitous immigrants might lurk in their own towns and villages.