After Britain declared war on Germany in September 1939, Hepburn's mother moved her daughter back to Arnhem in the hope that, as during the First World War, the Netherlands would remain neutral and be spared a German attack. While there, Hepburn attended the Arnhem Conservatory from 1939 to 1945. She had begun taking ballet lessons during her last years at boarding school, and continued training in Arnhem under the tutelage of Winja Marova, becoming her "star pupil". After the Germans invaded the Netherlands in 1940, Hepburn used the name Edda van Heemstra, because an "English-sounding" name was considered dangerous during the German occupation. Her family was profoundly affected by the occupation, with Hepburn later stating that "had we known that we were going to be occupied for five years, we might have all shot ourselves. We thought it might be over next week… six months… next year… that's how we got through". In 1942, her uncle, Otto van Limburg Stirum (husband of her mother's older sister, Miesje), was executed in retaliation for an act of sabotage by the resistance movement; while he had not been involved in the act, he was targeted due to his family's prominence in Dutch society. Hepburn's half-brother Ian was deported to Berlin to work in a German labour camp, and her other half-brother Alex went into hiding to avoid the same fate.