William I or Wilhelm I (Wilhelm Friedrich Ludwig; 22 March 1797 – 9 March 1888) was King of Prussia from 2 January 1861 and German Emperor from 18 January 1871 until his death in 1888. A member of the House of Hohenzollern, he was the first head of state of a united Germany. He was de facto head of state of Prussia from 1858, when he became regent for his brother Frederick William IV. During the reign of his grandson Wilhelm II, he was known as Wilhelm the Great ().
The second son of Prince Frederick William and Louise of Mecklenburg-Strelitz, William was not expected to ascend to the throne. His grandfather, King Frederick William II died the year he was born, and his father was crowned Frederick William III. William fought with distinction during the War of the Sixth Coalition, and afterwards became a prominent figure within the Prussian Army. In 1840, his childless elder brother became King of Prussia, making him heir presumptive. William played a major role in crushing the Revolutions of 1848 in Germany, although he was briefly forced into exile in England. Frederick William IV suffered a stroke in 1857 and was left incapacitated, and William was formally named Prince Regent a year later. In 1861, William ascended to the Prussian throne on his elder brother's death.
Upon ascension, William immediately came into conflict with the liberal Landtag over his proposed military budget. In response, he appointed Otto von Bismarck to the post of Minister President in order to force through his proposals, beginning a partnership that would last for the rest of his life. On the foreign front, William oversaw Prussian victories in the Second Schleswig War and the Austro-Prussian War, establishing Prussia as the leading German power. In 1871, through Bismarck's maneuvers, the unification of Germany was achieved following the Franco-Prussian War. The German Empire was proclaimed and William was granted the title of German Emperor. Even though he had considerable power as Kaiser, William largely left the affairs of the state to Bismarck. Later in life he was the target of multiple failed assassination attempts, which enabled Bismarck to push through a series of anti-socialist laws. In 1888, which came to be known as the Year of the Three Emperors, William died at the age of 90 after a short illness and was succeeded by his son Frederick. Frederick, already suffering from cancer, died 99 days later and the throne passed to Wilhelm II.
Early life and military career
The future king and emperor was born William Frederick Louis of Prussia () in the in Berlin on 22 March 1797. As the second son of Louise of Mecklenburg-Strelitz and Prince Frederick William, himself son of King Frederick William II, William was not expected to ascend to the throne. His grandfather died the year he was born, at age 53, in 1797, and his father Frederick William III became king. He was educated from 1801 to 1809 by , who was also in charge of the education of William's brother, the Crown Prince Frederick William. At age twelve, his father appointed him an officer in the Prussian army. The year 1806 saw the defeat of Prussia by France and the end of the Holy Roman Empire.
William served in the army from 1814 onward. Like his father, he fought against Napoleon I of France during the part of the Napoleonic Wars known in Germany as the ("Wars of Liberation", otherwise known as the War of the Sixth Coalition), and was reportedly a very brave soldier. He was made a captain () and won the Iron Cross for his actions at Bar-sur-Aube. The war and the fight against France left a lifelong impression on him, and he had a long-standing antipathy towards the French.
In 1815, William was promoted to major and commanded a battalion of the 1. Garderegiment. He fought under Gebhard Leberecht von Blücher at the Battles of Ligny and Waterloo. He became a diplomat, engaging in diplomatic missions after 1815. In 1817, he accompanied his sister Charlotte to Saint Petersburg, when she married Emperor Nicholas I of Russia, becoming Empress Alexandra Feodorovna.
In 1816, William became the commander of the and in 1818 was promoted to . The next year, William was appointed inspector of the VII. and VIII. Army Corps. This made him a spokesman of the Prussian Army within the House of Hohenzollern. He argued in favour of a strong, well-trained, and well-equipped army. In 1820, William became commander of the and in 1825 was promoted to commanding general of the III. Army Corps.