Princess Stephanie used her connections to spy on England for the Nazis. Wikipedia.

17. Princess Stephanie von Hohenlohe loved England, but she also loved the Nazis, so it was inevitable she became a secret agent of the Third Reich

Born Stephanie Julienne Richter in September of 1891, marriage to an Austrian prince at the age of just 23 made her Princess Stephanie von Hohenlohe – and she was determined to make full use of her title. From the very start, she behaved terribly. Indeed, she gained her royal title on false pretenses, tricking the Austrian prince that a child she was carrying was the result of a brief affair between them (the father was actually an Archduke). However, it was in the 1930s that Princess Stephanie really gained her notoriety – and earned herself the nickname of the ‘Nazi Princess’.

After divorcing her prince, Stephanie relocated to London. Here, she mingled with British aristocracy, while also making friends in high places in Nazi Germany. By the late-1930s, she was serving as a glamorous go-between, linking Hitler to rich, high-placed Brits, including Lord Rothermere, a hugely influential media baron. The Princess visited Germany on several occasions. By all accounts, Hitler himself adored her. However, in 1938, the Nazi regime started persecuting Austrian Jews. Stephanie’s ancestral past proved her downfall. She was interned in the United States for the duration of the war, moving back to Germany and enjoying a media career of her own once peace returned.