
Since he had no children, William was first in line to succeed him to the throne and thus was given the title Prinz von Preußen. In 1840 his older brother became King of Prussia.

Their marriage was outwardly stable, but not a very happy one. In 1829, William married Princess Augusta, the daughter of Grand Duke Karl Friedrich of Saxe-Weimar-Eisenach and Maria Pavlovna, the sister of Nicholas I. They had a family of three sons and two daughters. She married a Carl Friedrich Ludwig Dettman (known as "Louis") and emigrated to Sydney, Australia, in 1849. It is alleged that Elisa had an illegitimate daughter by William who was brought up by Joseph and Caroline Kroll, owners of the Kroll Opera House in Berlin, and was given the name Agnes Kroll. In 1826, William was forced to break off the relationship by his father, who deemed it an inappropriate match. Īround this time, William became romantically linked with his cousin. Gardedivision and in 1825 was promoted to commanding general of the III. In 1820, William became commander of the 1. He argued in favour of a strong, well-trained, and well-equipped army. This made him a spokesman of the Prussian Army within the House of Hohenzollern. The next year, William was appointed inspector of the VII. In 1816, William became the commander of the Stettiner Gardelandwehrbataillon and in 1818 was promoted to Generalmajor. In 1817, he accompanied his sister Charlotte to Saint Petersburg, when she married Emperor Nicholas I of Russia, becoming Empress Alexandra Feodorovna. He became a diplomat, engaging in diplomatic missions after 1815. He fought under Gebhard Leberecht von Blücher at the Battles of Ligny and Waterloo. In 1815, William was promoted to major and commanded a battalion of the 1. The war and the fight against France left a lifelong impression on him, and he had a long-standing antipathy towards the French.

He was made a captain ( Hauptmann) and won the Iron Cross for his actions at Bar-sur-Aube. Like his father, he fought against Napoleon I of France during the part of the Napoleonic Wars known in Germany as the Befreiungskriege ("Wars of Liberation", otherwise known as the War of the Sixth Coalition), and was reportedly a very brave soldier. William served in the army from 1814 onward. The year 1806 saw the defeat of Prussia by France and the end of the Holy Roman Empire. At age twelve, his father appointed him an officer in the Prussian army.

He was educated from 1801 to 1809 by Johann Friedrich Gottlieb Delbrück, who was also in charge of the education of William's brother, the Crown Prince Frederick William.

His grandfather died the year he was born, at age 53, in 1797, and his father Frederick William III became king. 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. The future king and emperor was born William Frederick Louis of Prussia ( Wilhelm Friedrich Ludwig von Preußen) in the Kronprinzenpalais in Berlin on 22 March 1797. Queen Louise of Prussia with her two eldest sons (later King Frederick William IV of Prussia and the first German Emperor William I), circa 1808 In contrast to the domineering Bismarck, William was described as polite, gentlemanly and, while staunchly conservative, more open to certain classical liberal ideas than his grandson Wilhelm II, during whose reign he was known as Wilhelm the Great ( German: der Große). Despite his long support of Bismarck as Minister President, William held strong reservations about some of Bismarck's more reactionary policies, including his anti-Catholicism and tough handling of subordinates. Under the leadership of William and his minister president Otto von Bismarck, Prussia achieved the unification of Germany and the establishment of the German Empire. He was de facto head of state of Prussia from 1858, when he became regent for his brother Frederick William IV, whose death three years later would make him king. A member of the House of Hohenzollern, he was the first head of state of a united Germany. William I or Wilhelm I ( German: 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.
