Elisabeth Christine of Brunswick-Wolfenbüttel in the context of "Maria Carolina of Austria"

Charles VI (German: Karl; Latin: Carolus; 1 October 1685 – 20 October 1740) was Holy Roman Emperor and ruler of the Austrian Habsburg monarchy from 1711 until his death, succeeding his elder brother, Joseph I. He unsuccessfully claimed the throne of Spain following the death of his relative, Charles II. In 1708, he married Elisabeth Christine of Brunswick-Wolfenbüttel, by whom he had his four children: Leopold Johann (who died in infancy), Maria Theresa, Maria Anna (Governess of the Austrian Netherlands), and Maria Amalia (who also died in infancy).

Four years before the birth of Maria Theresa, faced with his lack of male heirs, Charles provided for a male-line succession failure with the Pragmatic Sanction of 1713. The Emperor favoured his own daughters over those of his elder brother and predecessor, Joseph I, in the succession, ignoring the Mutual Pact of Succession he had signed during the reign of his father, Leopold I. Charles sought the other European powers' approval. They demanded significant terms, among which were that Austria close the Ostend Company. In total, the states of Great Britain, France, Saxony-Poland, the Dutch Republic, Spain, Venice, the Papal States, Prussia, Russia, Denmark, Savoy-Sardinia, and Bavaria, plus the Diet of the Holy Roman Empire, recognised the sanction. France, Spain, Saxony-Poland, Bavaria, and Prussia later reneged. Charles died in 1740, sparking the War of the Austrian Succession, which plagued his successor, Maria Theresa, for eight years.

The Pragmatic Sanction of 1713 (Latin: Sanctio Pragmatica; German: Pragmatische Sanktion) was an edict issued by Holy Roman Emperor Charles VI, on 19 April 1713 to ensure that the Habsburg monarchy, which included the Archduchy of Austria, the Kingdom of Hungary, the Kingdom of Croatia, the Kingdom of Bohemia, the Duchy of Milan, the Kingdom of Naples, the Kingdom of Sardinia and the Austrian Netherlands, could be inherited by a daughter undivided.

As of 1713, Charles and his wife Elizabeth Christine had not had any children. Since the death of his elder brother, Joseph I, in 1711, Charles had been the sole surviving male member of the House of Habsburg. Joseph had died without male issue, leaving Joseph's daughter Maria Josepha as the heiress presumptive. That presented two problems. First, a prior agreement with his brother, known as the Mutual Pact of Succession (1703), had agreed that in the absence of male heirs, Joseph's daughters would take precedence over Charles's daughters in all Habsburg lands. Though Charles had no children, if he were to be survived by daughters alone, they would be cut out of the inheritance. Secondly, because Salic law precluded female inheritance, Charles VI needed to take extraordinary measures to avoid a protracted succession dispute, as other claimants would have surely contested a female inheritance.