King Frederick William III of Prussia reigned from 1797 to 1840. He was born on August 3, 1770, and was the son of Frederick William II. His reign was marked by the challenges of the Napoleonic Wars, during which he faced significant military defeats and territorial losses. Frederick William III is known for his efforts to reform the Prussian state after the wars. He initiated various administrative and military reforms, aiming to modernize Prussia. His reign also saw the rise of nationalist sentiments, which eventually contributed to the unification of Germany in the latter half of the 19th century.