"Princess Stéphanie of Belgium (21 May 1864 – 23 August 1945), a Belgian princess by birth, became Crown Princess of Austria through her marriage to the heir-apparent of the Habsburg dynasty, Archduke Rudolf. She was famously widowed in 1889 when Rudolf and his mistress, Mary Vetsera, were found dead in an apparent murder-suicide pact at the Imperial hunting lodge at Mayerling in the Vienna Woods.
Her grandfather Leopold I of Belgium was the country´s first king. Her aunt, Charlotte of Belgium, the future ill-fated Empress of Mexico, was married to Maximilian, the brother of her future father-in law, the Austrian Emperor Franz Joseph." - (en.wikipedia.org 12.02.2020)
)