It is rare for the death of a young child to shift the balance of European power and trigger a full-scale war. Yet that is precisely what happened when six-year-old Joseph Ferdinand of Bavaria died on 6 February 1699.
By the late 1690s, it was clear that Charles II would be the last Spanish Habsburg on the throne. As the ultimate product of generations of inbreeding, he was physically and mentally incapable— to put it mildly. Thus, the change of ruling dynasty was only a matter of time.
The two main candidates for succession, an Austrian archduke and a Bourbon prince, each had fierce supporters and opponents, whose disagreements divided the Spanish court. In this antagonistic situation, many saw Joseph Ferdinand of Bavaria as a strong alternative. He was neither a Habsburg nor a Bourbon, yet as the only surviving grandchild of Margarita Teresa, the elder sister of Charles II, his claim to the Spanish throne was equal to that of the other two contenders. As a result, the influential ‘Bavarian’ faction at court was able to gather considerable support.
Curiously enough, the two people least involved in the matter were Charles II and Joseph Ferdinand themselves. The king was mentally incapable of handling complex matters of state, and the young Bavarian prince was hardly more than a toddler. Their deaths, within just 20 months of each other, set off the War of the Spanish Succession, which lasted for 14 years.