William I, 1772–1843, first king of the Netherlands and grand duke of Luxembourg (1815–40), son of Prince William V of Orange, last stadtholder of the Netherlands. He commanded (1793–95) the Dutch army in the French Revolutionary Wars, and after the French occupation of the Netherlands he entered the Prussian and later the Austrian service. He returned to the Netherlands in 1813, and the Congress of Vienna gave him (1815) the title king of the Netherlands. His kingdom comprised present Belgium as well as the Netherlands, and he was awarded the grand duchy of Luxembourg in compensation for his family holdings in Germany, which he ceded to Prussia. William soon alienated his Belgian subjects by attempting to make Dutch the official language, by granting disproportionate influence to the northern provinces, and by encroaching on the freedom of the Roman Catholic Church. Political unrest in Belgium led to the revolution of 1830, which he stubbornly sought to suppress despite the intervention of England and France (see London Conference). Belgium won its independence, but final recognition by William came only in 1839. When his Dutch subjects forced him to liberalize the constitution in 1840, he abdicated in favor of his son William II. Through his rule as an enlightened despot, William fostered the development of Dutch agriculture, commerce, and industry.