<P> The people of the south were mainly Dutch - speaking Flemings and French - speaking Walloons . Both peoples were traditionally Roman Catholic as contrasted with the Dutch Reformed in the north . Many outspoken liberals regarded King William I's rule as despotic . There were high levels of unemployment and industrial unrest among the working classes . </P> <P> On 25 August 1830, riots erupted in Brussels and shops were looted . Theatregoers who had just watched the nationalistic opera La muette de Portici joined the mob . Uprisings followed elsewhere in the country . Factories were occupied and machinery destroyed . Order was restored briefly after William committed troops to the Southern Provinces but rioting continued and leadership was taken up by radicals, who started talking of secession . </P> <P> Dutch units saw the mass desertion of recruits from the southern provinces and pulled out . The States - General in Brussels voted in favour of secession and declared independence . In the aftermath, a National Congress was assembled . King William refrained from future military action and appealed to the Great Powers . The resulting 1830 London Conference of major European powers recognized Belgian independence . Following the installation of Leopold I as "King of the Belgians" in 1831, King William made a belated military attempt to reconquer Belgium and restore his position through a military campaign . This "Ten Days' Campaign" failed because of French military intervention . Not until 1839 did the Dutch accept the decision of the London conference and Belgian independence by signing the Treaty of London . </P> <P> The Dutch overthrew Napoleonic rule in 1813 and, after the British - Dutch Treaty of 1814, named their state the "United Provinces of the Netherlands" or simply the "United Netherlands". After the defeat of Napoleon in 1815, the Congress of Vienna created a kingdom for the House of Orange - Nassau, thus combining the United Provinces of the Netherlands with the former Austrian Netherlands in order to create a strong buffer state north of France; with the unification of all the provinces the Netherlands was indeed a rising power . Symptomatic of the tenor of diplomatic bargaining at Vienna was the early proposal to reward Prussia for its staunch fight against Napoleon with the former Habsburg territory . When the British insisted on retaining the former Dutch Ceylon and the Cape Colony (which they had seized while the Netherlands was ruled by Napoleon) the new kingdom of the Netherlands was compensated with these southern provinces (modern Belgium). The union of these two areas reverted to the original cultural area of the Netherlands before the 16th century and were called the "United Kingdom of the Netherlands". </P>

When belgium declared its independence in 1830 it broke away from ___ control