Frederick William III was King of Prussia from 16 November 1797 until his death in 1840. He was concurrently Elector of Brandenburg in the Holy Roman Empire until 6 August 1806, when the empire was dissolved.

In the War of the Sixth Coalition, sometimes known in Germany as the Wars of Liberation, a coalition of Austria, Prussia, Russia, Spain, Great Britain, Portugal, Sweden, Sardinia, and a number of German States defeated France and drove Napoleon into exile on Elba. After the disastrous French invasion of Russia of 1812 in which they had been forced to support France, Prussia and Austria joined Russia, the United Kingdom, Sweden, and Portugal, and the rebels in Spain who were already at war with France.