PODIn 1759 Russia and Austria were surrounding Berlin, poised to destroy the city and Frederich II's Prussian Army.
Frederich was considering suicide if Berlin fell and he almost did but Elisabeth of Russia died and her son, Peter III, became Tsar of Russia and stopped the war with Prussia.
But what if Elisabeth of Russia had instead survived for just six more months and the Austrians and Russians were able to attack and burn Berlin and execute Frederich II.
This victory would've ended the Seven Year's War in Europe as Prussia would've been reduced to Brandenburg, Silesia returned to Austria, southern territories given to Saxony and East Prussia granted to Poland in exchange for Russia gaining eastern Poland. Brandenburg and the Prussians would never be a threat to European stability, but perhaps the greastest German power, Austria and the Hapsburg dynasty would be able to enact their dream of Großdeutschland.