Maria Antonia of Austria

Maria Antonia of Austria (Marie Antonia von Österreich) (Maria Antonia Josepha Benedicta Rosalia Petronella; 18 January 1669 – 24 December 1692) was the eldest daughter and only surviving child of Leopold I, Holy Roman Emperor and his first wife Margaret Theresa of Spain. She became the heiress to Habsburg Spain when her mother died in 1673. She became an electress of the Electorate of Bavaria after marrying Maximilian II Emanuel in 1685, when she was 12 years old. Maria Antonia died of postpartum infections / sepsis, aged 23, after the birth of her third child; all of her children died in infancy or childhood. She did not live long enough to accede to the throne of Spain.

The early deaths of Maria Antonia and her sons, which were likely indirectly due to generations of inbreeding, left the Kingdom of Spain without a ruler upon the death of Charles II of Spain in 1700. This led to the War of the Spanish Succession (1701-1714), in which 700,000 people died in 13 years.

Maria Antonia had the highest coefficient of inbreeding in the House of Habsburg; her father was her mother's maternal uncle and paternal first cousin once removed, and her maternal grandparents were uncle and niece. She did not display any noticeable physical deformities that are normally accompanied by inbreeding, although portraits of her were likely embellished for political purposes and her genetics likely exacerbated the infection that led to her death.