Who was nicknamed Sisi?

Elisabeth of Bavaria (24 December 1837 – 10 September 1898) was Empress of Austria and Queen of Hungary by marriage to Emperor Franz Joseph I. Elisabeth was born into the royal Bavaria house of Wittelsbach. Nicknamed Sisi, she enjoyed an informal upbringing before marrying Emperor Franz Joseph I at the age of sixteen.

Early in the marriage she was at odds with her mother-in-law, Archduchess Sophie, who took over the rearing of Elisabeth's daughters, one of whom, Sophie, died in infancy. The birth of the heir apparent, Crown Prince Rudolf, improved her standing at court, but her health suffered under the strain, and she would often visit Hungary for its more relaxed environment. She came to develop a deep kinship with Hungary, and helped to bring about the dual monarchy of Austria–Hungary in 1867.

The death of her only son and his mistress Mary Vetsera, in a murder–suicide at his hunting lodge at Mayerling in 1889 was a blow from which Elisabeth never recovered. She withdrew from court duties and travelled widely. In 1890, she had a palace built on the Greek Island of Corfu that she visited often. The palace Achilleion, featuring an elaborate mythological motif, served as a refuge. She was obsessively concerned with maintaining her youthful figure and beauty, which were already legendary during her life. While travelling in Geneva in 1898, she was mortally wounded by an Italian anarchist named Luigi Lucheni. She was the longest serving Empress of Austria at 44 years.