A death of a middle aged woman in St. Petersburg changed history. In 1762 towards the end of the Seven Years War, Prussia was on the verge of collapse. Having lost his last Baltic port and with his army almost annihilated, Frederick the Great at times seriously contemplated suicide. The consequences for Prussia were dire. Starting with the Great Elector, over the previous 100 years the Electors of Brandenburg had established one of the finest armies in Europe, acquired the royal crown in Prussia and seized the rich province of Silesia from the Hapsburgs. Now Frederick’s implacable foe the Tsarina Elizabeth (daughter of Peter the Great) was on the verge of humbling the Prussian upstart. In addition to the loss of Silesia, Frederick also faced the prospect of the loss of his royal title and the prestige his House had accumulated.
And then the “Miracle of the House of Brandenburg” occurred.
On January 5, 1762 (December 25, 1761 under the Julian Calendar) the Tsarina died unexpectedly. Her notoriously pro-Prussian successor Peter III promptly removed Russia from the war giving a gasping Prussia time to catch its breath and drive the Austrians from Silesia. Even though Peter III was deposed by his wife Catherine II a few months later and Russia reentered the war, the interval had changed the strategic position on the ground.
In the resulting peace treaty Prussia retained Silesia and gained the prestige of having fought off the far larger states of France, Austria and Russia. Prussia had forced itself into the ranks of the major powers of Europe and would expand further during the partitions of Poland. The Congress of Vienna expanded the Prussian state further by giving it a slice of Saxony, the Rhineland and Westphalia. This enhanced Prussian state would be the focus of nationalistic German aspirations. The unification of Germany under the militaristic Prussian state would have additional consequences in the 20th century.
The Prussian state still had to overcome the incompetence of Frederick’s next three successors and survive a series of crises and disasters in the Napoleonic wars. But a neutered Prussian state stripped of Silesia and the economic bounty that province provided, without the reinforcement of the state institutions by Frederick after the war and forced to accept a humiliating peace could have fallen back into the second tier status of previous German contenders Bavaria and Saxony.
With a disastrous defeat in the Seven Years War, Prussia may have ended up a bit player rather than a prime mover in the partitions of Poland. Prussia may not have been able to prevent Joseph II‘s attempted acquisition of Bavaria which would have significantly enhanced the German component of the rickety Hapsburg monarchy. The absence of a Prussian counterweight to Austria would have altered the contours of German history.
While the nationalistic movements in the 19th century would likely still have created a German State, it would likely have been very different than the militarized Prussian Empire Bismarck cobbled together. It could have ended up as a looser grouping of powers under Austrian hegemony (a reorganized Holy Roman Empire), or a Germany divided between the protestant North and East and the Catholic South and West. It is not clear any German state other than Prussia or Austria would have had the heft to unify Germany.
And it happened because of a death in St. Petersburg.