[1] At first, the British government took a relaxed attitude to the tens of thousands of "enemy aliens", most of them refugees who had found sanctuary in Britain from the Nazis.
But a panic following the fall of France and the invasion scare in May/June 1940 led to a mass round-up of most Germans in Britain, regardless of their political allegiances.
When Italy joined the war thousands of Italians were rounded up too, also irrespective of their political allegiances or how long they had lived in Britain.
From that point on, the internees were gradually released from their holding camps in Britain, leaving only a handful of confirmed Nazis and Fascists.
The book won very favourable reviews when it was published, and became the standard reference source on that topic, until the issue was reopened twenty years later.