William I (Willem Frederik; 24 August 1772 – 12 December 1843) was King of the Netherlands and Grand Duke of Luxembourg from 1815 until his abdication in 1840.
Born as the son of William V, Prince of Orange, the last stadtholder of the Dutch Republic, and Wilhelmina of Prussia, William experienced significant political upheavals early in life. He fought against the French invasion during the Flanders campaign, and after the Batavian Revolution in 1795, his family went into exile. He briefly ruled the Principality of Nassau-Orange-Fulda before Napoleon's French troops' occupation forced him out of power. Following the defeat of Napoleon in 1814, William was invited back to the Netherlands, where he proclaimed himself Sovereign Prince of the United Netherlands.
In 1815, William raised the Netherlands to a kingdom and concurrently became the grand duke of Luxembourg. His reign saw the adoption of a new constitution, which granted him extensive powers. He was a strong proponent of economic development, founding several universities and promoting trade. However, his efforts to impose the Reformed faith and the Dutch language in the mostly Catholic and partly French-speaking southern provinces, combined with economic grievances, sparked the Belgian Revolution in 1830. Unable to suppress the rebellion, William ultimately accepted Belgian independence in 1839 under the Treaty of London.
William's later years were marked by dissatisfaction with constitutional changes and personal reasons, leading to his abdication in 1840 in favor of his son, King William II. He spent his final years in Berlin, where he died in 1843.
William was the son of William V, Prince of Orange, the last stadtholder of the Dutch Republic, and Wilhelmina of Prussia. During the Flanders campaign, he commanded the Dutch troops and fought against the French invasion. The family went into exile in London in 1795 following the Batavian Revolution. As compensation for the loss of his father's possessions in the Low Countries, William was appointed ruler of the newly created Principality of Nassau-Orange-Fulda in 1803. When Napoleon invaded Germany in 1806, William fought on the Prussian side and was deposed upon French victory. With the death of his father in 1806, he became Prince of Orange and ruler of the Principality of Orange-Nassau, which he also lost the same year after the dissolution of the Holy Roman Empire and subsequent creation of the Confederation of the Rhine. He spent the following years in exile in Prussia. In 1813, following Napoleon's defeat at Leipzig, the Orange-Nassau territories were restored to William; he also accepted the offer to become Sovereign Prince of the United Netherlands.
William proclaimed himself king of the Netherlands in 1815. In the same year, he concluded a treaty with King Frederick William III in which he ceded the Orange-Nassau to Prussia in exchange for becoming the new grand duke of Luxembourg. As king, he adopted a new constitution, presided over strong economic and industrial progress, promoted trade and founded the universities of Leuven, Ghent and Liège. The imposition of the Reformed faith and the Dutch language, as well as feelings of economic inequity, caused widespread resentment in the southern provinces and led to the outbreak of the Belgian Revolution in 1830. William failed to crush the rebellion and in 1839 he accepted the independence of Belgium in accordance with the Treaty of London.
William's disapproval of changes to the constitution, the loss of Belgium and his intention to marry Henrietta d'Oultremont, a Roman Catholic, led to his decision to abdicate in 1840. His eldest son acceded to the throne as King William II. William died in 1843 in Berlin at the age of 71.
King William I's parents were the last stadtholder William V, Prince of Orange of the Dutch Republic, and his wife Wilhelmina of Prussia. Until 1806, William was formally known as William VI, Prince of Orange-Nassau, and between 1806 and 1813 also as Prince of Orange. In Berlin on 1 October 1791, William married his maternal first cousin (Frederica Louisa) Wilhelmina of Prussia, born in Potsdam. She was the daughter of King Frederick William II of Prussia. After Wilhelmina died in 1837, William married Countess Henrietta d'Oultremont (28 February 1792, in Maastricht – 26 October 1864, in Schloss Rahe), created countess of Nassau, on 17 February 1841, also in Berlin.
Youth and early military career
As eldest son of the William V, Prince of Orange, William was informally referred to as Erfprins (Hereditary Prince) by contemporaries from his birth until the death of his father in 1806 to distinguish him from William V.
Like his younger brother Prince Frederick of Orange-Nassau he was tutored by the Swiss mathematician Leonhard Euler and the Dutch historian Herman Tollius. They were both tutored in the military arts by General Frederick Stamford. After the Patriot revolt had been suppressed in 1787, he in 1788–89 attended the military academy in Brunswick which was considered an excellent military school, together with his brother. In 1790 he visited a number of foreign courts like the one in Nassau and the Prussian capital Berlin, where he first met his future wife.
William subsequently studied briefly at the University of Leiden. In 1790 he was appointed a general of infantry in the Dutch States Army of which his father was Captain general, and he was made a member of the Council of State of the Netherlands. In November 1791 he took his new bride to The Hague.
After the National Convention of the French Republic had declared war on the Dutch Republic in February 1793, William was appointed commander-in-chief of the veldleger (mobile army) of the States Army (his father remained the nominal head of the armed forces). As such he commanded the troops that took part in the Flanders Campaign of 1793–95. He took part in the Battles of Veurne and Menin (where his brother was wounded) in 1793, and commanded during the Siege of Landrecies (1794), whose fortress surrendered to him. In May 1794 he had replaced general Kaunitz as commander of the combined Austro-Dutch forces on the instigation of Emperor Francis II who apparently had a high opinion of him. William was victorious at the Battles of Gosselies and Lambusart and proved to be an able commander, but the French armies ultimately proved too strong, and the general allied leadership too inept. Despite a well-executed attack by William on the French left, the allied army under Coburg was finally defeated at the Battle of Fleurus. The French first entered Dutch Brabant which they dominated after the Battle of Boxtel. When in the winter of 1794–95 the rivers in the Rhine delta froze over, the French breached the southern Hollandic Water Line and the situation became militarily untenable. In many places Dutch revolutionaries took over the local government. After the Batavian Revolution in Amsterdam on 18 January 1795 the stadtholder decided to flee to England, and his sons accompanied him. (On this last day in Holland his father relieved William honorably of his commands). The next day the Batavian Republic was proclaimed.
Soon after the departure to England the hereditary prince went back to the continent, where his brother was assembling former members of the States Army in Osnabrück for a planned invasion into the Batavian Republic in the summer of 1795. However, the neutral Prussian government forbade this.
In 1799, William landed in modern-day North Holland as part of the Anglo-Russian invasion of Holland. He was instrumental in fomenting a mutiny among the crews of a Batavian Navy squadron under Rear-Admiral Samuel Story, resulting in the squadron surrendering without a fight to the Royal Navy, which accepted the surrender in the name of the stadtholder. Not all the local Dutch population, however, was pleased with the arrival of the prince. One local Orangist was even executed. The hoped-for popular uprising failed to materialise. After several minor battles the hereditary prince was forced to leave the country again after the Convention of Alkmaar. The mutineers of the Batavian fleet, with their ships, and a large number of deserters from the Batavian army accompanied the retreating British troops to Britain. There William formed the King's Dutch Brigade with these troops, a military unit in British service, that swore oaths of allegiance to the British king, but also to the States General, defunct since 1795, "whenever those would be reconstituted." This brigade trained on the Isle of Wight in 1800 and was stationed in Ireland for a time.