1830 - Declaration of independence from Netherlands. Belgian army holds position behind Yser river until 1918. 1920 - Belgium abandons neutrality and signs military alliance with France. 1930 - Flanders and Wallonia legally become unilingual regions. World War II 1940 - Germany invades Belgium and Holland.
Belgian government evacuates to London.
King Leopold surrenders to German forces. 1950 - Belgian electorate votes for Leopold's return, but after strikes and riots Leopold appoints eldest son, Prince Baudouin, to temporarily rule in his place. 1951 - Baudouin officially assumes kingship. 1958 - Belgium, Netherlands and Luxembourg form Benelux Economic Union to promote free movement of workers, goods and services in the region. Federal government 1992 - Belgium ratifies Maastricht Treaty on European union.