William I of Germany, also known as William I, German Emperor, was born on March 22, 1797. He became the King of Prussia in 1861 and later the first German Emperor in 1871 after the unification of Germany. His reign marked a significant period in European history, characterized by military expansion and industrial growth. William I played a crucial role in the Franco-Prussian War (1870-1871), which helped solidify German unity. His leadership and support for Chancellor Otto von Bismarck were instrumental in the establishment of the German Empire. He ruled until his death on March 9, 1888.