And another irony, as I discovered when I lived in Berlin in 1987, was that for the first 30-odd years of the last century, German was the international language of science. Scientists from other countries, including Britain, learned to speak and write German, attended conferences using the German language and publishing their papers written in German. It was eye-opening for me to visit the many (excellent) Berlin museums and realise that, largely because of the brilliance of their scientists, especially physicists and chemists, Germany had become the de facto centre of the scientific world.

Then, after the National Socialists came to power, from 1933 onwards, the majority of the best scientists left Germany, mostly coming to Britain or the United States. They learned English and gradually English became the international scientific language, and, eventually, the international language of commerce, entertainment and so on.

The irony is that Hitler and the National Socialists wanted Germans to rule the world but their actions had the opposite effect.