The original Celtic tribes of the North Sea coastal regions became part of the Roman Empire when they were conquered in 57 B.C. by the armies of Julius Caesar. (The name "Belgium" derives from the original inhabitants of the region, labeled the Gallia Belgica by the Romans.) During this time, the inhabitants of southern Belgium were heavily influenced by Latin culture, giving rise to Latinate cultural traditions and the use of a Latin language. In the north, the cultural influence of Rome was weaker. The invasion of Salian Franks in the fifth century abruptly interrupted the period of Latin Influence and established a Germanic Frankish kingdom, which included the use of a Germanic language. The linguistic border that crosses Belgium is believed to mark the extent of Frankish influence. In the ninth century, Charlemagne united independent Frankish regions into a vast kingdom, of which Flanders was a central part. In the division of Charlemagne's kingdom upon his death, Flanders came under the control of his son, Lothair, comprising Lotharingia. Weak governments under Lothair and his successors resulted in a process of fragmentation that gave rise to the feudal period, extending from the ninth to the twelfth centuries ( A.D. 862-1128), during which distinct principalities, counties, and duchies were established. The county of Flanders, the duchy of Brabant, and the bishopric of Liege were three of the most politically dominant. In spite of political, organizational, and language divisions, similar cultural traditions and a prosperous textile industry led to a degree of political cooperation Between districts. From 1128 to 1278, the authority of nobles was challenged by the growing political power of city-dwelling burghers who gained political and military control of Transportation and trade. During the Burgundian period, 1384—1482, a series of noble marriages and alliances unified the smaller principalities while preserving and extending citizen authority and the relative economic autonomy of cities. During the fifteenth and sixteenth centuries, under a balance of power between nobles and free citizens, Flemish cities established a trade association in London and became central to trans-European trade, as members of the German Hanse. This period, considered the golden age of Flemish culture, produced great works of art and music. However, the process of consolidation into yet larger political bodies was not favorable for the Flemish. When Flanders became part of the Kingdom governed by the Spanish Habsburgs (1506-1700), the people became subject to authoritarian structures foreign to developing cultural traditions. The rule of the Spanish proved disastrous for the Flemish people; during the years of the Spanish Inquisition, many were tortured or killed for religious and political dissent. In an attempt to end Spanish rule, the region went to war against Spain, resulting in the separation of the northern from the southern Flemish, the creation of the independent nation of Holland comprised of liberated northern provinces, and the continued subjugation of the "Spanish Netherlands." The Flemish and the French-speaking Walloons continued to live under the Spanish until the War of Spanish Succession, 1700-1713, when the Territories passed to the Austrian Habsburgs. During this period, French became the dominant language for social and Political life; the Flemish became marginalized as a national identity grew. In 1794, Napoleon conquered and annexed the Flemish and Walloon territories for France. After his defeat in 1815, the Treaty of Vienna assigned these areas to the new kingdom of the Netherlands, under the rule of King William I. However, the years of economic and political separation between the Dutch and the Flemish, the years of a Common fate with Wallonia, and the quite different economic and political positions of the Dutch and the Belgians in a world economy proved to be stronger political factors than a common heritage in a more distant past. Belgians—both Walloons and Flemish—revolted against the Dutch in 1830, proclaiming Belgium as an independent nation. In 1831, they elected Prince Leopold of Saxe-Coburg-Gotha as king, defined their government as a constitutional monarchy, and Instituted a bicameral parliament with democratic representation. Although Flemish leaders were an integral part of Belgian independence efforts, the Flemish played a minority role in national politics until the early 1900s, because of the predominance of French language and culture during the period of French and Austrian control. In 1914, Germany invaded Belgium. Many of the battles of World War I were fought in Flanders, which sustained enormous damage in both urban and rural areas and suffered great loss of life. Again, in 1940, Germany invaded. In an attempt to avoid the devastation it had suffered in World War I, the king quickly surrendered to the Germans. The strategy was ineffective and deadly. Belgian Jews and Gypsies were exported and killed by the Nazis. Many Flemish and Walloons were conscripted and sent to work in German factories and labor camps. The nation was occupied and became one of the most embattled fronts of the war, in both Wallonia and Flanders. In 1944, Belgium was liberated by Canadian, Australian, and American forces. The postwar period was a time of rebuilding, but it was also internally divisive and disruptive for the Belgian People. German collaborators were punished, and the king was forced to give up his rule to his son. Partly because of the favoritism shown by the Germans for the Flemish during the war, ethnic tensions between Flemish and Walloon increased. Also, Belgian colonial holdings in Africa were lost either through civil unrest or the granting of independence to restive former colonies. During the 1960s and 1970s, ethnic divisiveness in Belgium was largely resolved with the creation of independent Flemish and Walloon assemblies, which each have authority over cultural, social, political, and regional administrative affairs of their respective groups. At this time Flemish was recognized as an official state language. The Flemish regions also gained in relative economic importance, while Wallonia experienced a decline in the heavy industries—notably in steel and coal. Flanders's importance rose as well in international trade, high-tech manufacturing, industrial agriculture, tourism, and fishing. Today, the Flemish enjoy full political and social equality with the Walloons.