William I of the Netherlands

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.

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.