Ilse Pröhl came from a national-conservative family. She was one of the three daughters of Friedrich Pröhl, a wealthy Hanoverian physician, and his wife Elsa, née Meineke. Her father was killed during the Kapp Putsch. In March 1920, the Freikorps unit known as the Ehrhardt Brigade with swastikas on their helmets, the uprising or coup d etat led by nationalist politician Wolfgang Kapp and General Walther von Lüttwitz, seized power in Berlin for five days. The coup failed, and during the brigade’s retreat, it carried out a massacre, firing into crowds of protesters. Ilse Hess’s father was killed in this fighting as one of the Freikorps’ “national warriors.” The brigade’s commander, Hermann Ehrhardt, lived undisturbed in Austria’s Waldviertel region only 60 km north from Vienna  until his death in 1971. Whether by coincidence or not, Adolf Hitler’s family also originated from the Waldviertel.