Frederick William III was the King of Prussia from 1797 until his death in 1840. He was born on October 3, 1770, and became king after the death of his father, Frederick William II. His reign was marked by the challenges of the Napoleonic Wars and the subsequent reforms in Prussia. During his rule, Frederick William III focused on modernizing the Prussian state and military. He supported the establishment of a constitutional monarchy and implemented various social and economic reforms. His leadership helped shape the future of Prussia and laid the groundwork for the eventual unification of Germany.