Prussia

On 29 August 1756, Frederick the Great invaded Saxony, igniting the Seven Years' War in Europe. Prussia survived a suicidal war against three empires not merely through tactical genius, but through allied paralysis and a stroke of Russian luck.

On 7 July 1807, France and Russia signed the Treaty of Tilsit after a staged reconciliation on a raft in the Neman. Prussia was carved in half two days later. The alliance it built was the high point of Napoleon's power and the start of its unravelling.