Born at Laxenburg, and known as Erzsi, Archduchess Elisabeth Marie was Rudolf and Stephanie’s only child. Franz Josef would not allow his favourite granddaughter to be taken away from Austria by his mother. In 1901 she decided to marry Prince Otto Windisch-Graetz and had to renounce her claim to the throne to prevent succession disputes. They had three sons and a daughter.
Throughout the marriage Elisabeth Marie and Otto had affairs before separating after the First World War. She joined the Social Democrats and in 1924 met Leopold Petznek, a teacher whose parents were small farmers. Nicknamed the red archduchess, she and Leopold bought a villa in the Viennese Huttelsdorf district.
Erzsi and her mother had a poor relationship leading Stephanie to disinherit her. Leopold survived the war despite being imprisoned in Dachau in 1944 and finally they were free to marry in 1948. He became President of the Austrian Court of Audit. They are both buried in an unmarked grave in Hutteldorfer cemetery. Against the wishes of her family Elisabeth Marie left more than 500 items to the Austrian state, many of which can be seen in Vienna’s museums.