Margaret Theresa of Spain, the first wife of Leopold I, passed away on 12 March 1673. She was the daughter of Philip IV of Spain and Mariana of Austria, the sister of Leopold. It is somewhat simplifying to say that the spouses were uncle and niece; owing to the Habsburgs’ persistent intermarriage, their parents, grandparents, and even great-grandparents already shared the same degree of consanguinity.
Margaret Theresa’s upbringing was designed to prepare her for the future role of Empress — above all, to provide the dynasty with sons. The fifteen-year-old princess arrived in Vienna and married Leopold, eleven years her senior, in 1666. Given the great hopes placed upon the union, it could easily have been called the wedding of the century. The splendid celebrations — considered among the most magnificent of the Baroque era — lasted nearly two years, curiously almost a third of the couple’s married life.
Reality, however, made its own corrections. After enduring six pregnancies within six years and being in the midst of a seventh, the exhausted Empress died at the age of twenty-one. Only one of her children, her daughter Maria Antonia of Austria, survived. Despite deep mourning, Leopold — still without a male heir — remarried only four months later.