The political power dynamics in Europe centred on religious friction and competing territorial claims. One of the more contentious issues of territory concerned the Houses of Habsburg and Bourbon. The Habsburgs had provided Holy Roman Emperors in a continuous line of father to son, brother or grandson, from Frederick III in the mid-fifteenth century to Leopold I in the eighteenth. Towards the end of his reign and two years into the War of the Spanish Succession, Leopold formulated a Mutual Pact of Succession with his sons. Signed on 12 September 1703, the pact held that his elder son, Joseph, later Joseph I, would succeed to the core Habsburg dominions of Austria, Hungary, Croatia and Bohemia, while Charles, his younger son, would claim Spain and its dominions in Europe and Spanish America. The pact also specified their respective line of succession, with each committing to being succeeded by his own son; however, it was also agreed that should there fail to be a male heir in either line, the surviving brother would succeed instead. If neither brother produced a male heir, Joseph’s daughters would take precedence and inherit the Habsburg estates as a whole.

Joseph I died in 1711 with no male heirs. Charles inherited and was elected Holy Roman Emperor as Charles VI. Two years later the War of the Spanish Succession ended with the Treaties of Utrecht and Rastatt signed in 1713 and 1714 respectively. But Spain was not absorbed by either the French Bourbons or Austrian Habsburgs. It was agreed instead that Philip, Duc d’Anjou, Louis XIV’s grandson, would be crowned king of Spain with the proviso that he renounce his right to the French throne and thereby void the possibility of a single Bourbon monarch uniting Spain and France, a combination that would threaten the rest of Europe. Philip was also forced to relinquish part of Spain’s territories. Austria gained the kingdoms of Naples and Sardinia, the major part of Milan, and the Spanish Netherlands; Sicily went to the Duke of Savoy; and Gibraltar and Minorca were ceded to Britain, which also gained trading access to Spanish America.

In the wake of this pan-European settlement, Charles VI formally abandoned the Mutual Pact of Succession and promulgated a decree that established new parameters for the Habsburg domains. Known as the Pragmatic Sanction, it dictated that the Habsburg estates would be inherited by his eldest son but should there be no male heir, the estates would pass not to Joseph I’s daughters but to his own. Only if Philip’s daughters died without issue would the estates revert to Joseph I’s daughters and their descendants. Lastly, in the event that one of Charles’s daughters succeeded, her husband would be eligible for election as Holy Roman Emperor.

Charles VI had a son in 1716 but he died within a year. His next two children were daughters: Maria Theresa born in 1717; and Maria Anna, in 1718. Royal conception was afterwards problematic and with a increasingly slim prospect of a male heir, Charles VI became obsessed with getting Europe to agree to uphold the Pragmatic Sanction.

The hereditary territories and states that made up the Habsburg’s sphere of influence were governed separately with different laws of succession and Charles VI insisted that his Pragmatic Sanction be recognised in each. The states were told of the terms formally in March 1720 and each signified their consent, the last signing in 1725. Two, Saxony and Bavaria, would later renege. Both the Prince-Elector of Saxony, married to Maria Josepha, Joseph I’s elder daughter, and the Prince-Elector of Bavaria, married Maria Amalia, his younger, would later assert a right of inheritance.

Elsewhere in Europe the Pragmatic Sanction was viewed not as a matter of Habsburg inheritance but as having a direct impact on the balance of political power. Austria, the seat of Habsburg influence, ruled or influenced a swathe of territories from the Austrian Netherlands, Milan, Tuscany and Naples, to a stretch of Central and Eastern Europe reaching from the Tyrol, Bohemia and Silesia to Hungary and Transylvania. And although the various prince-electors, lords and bishops within the states that owed their allegiance to the Holy Roman Emperor had de facto independence within their territories, Vienna’s influence was sizable.

Charles VI’s fixation opened Austria to political blackmail from France, Prussia and Spain, which wanted the return of the territories ceded at Utrecht. And although Britain had no territorial claims in continental Europe bar Gibraltar (albeit that Hanover had its own interests), London saw an opportunity to press its diplomatic advantage. Intercepted despatches and guidance from Austria’s diplomats indicated what Charles VI would be willing to sacrifice to achieve his goals and London manoeuvred to reach an accord. It transformed what had been an uneasy political relationship with Vienna into one of mutual accommodation and brought to a close the Anglo-French consensus of the prior three decades.