Which ethnic groups are you talking about? The French and the Dutch? Belgium used to be part of the Netherlands through 1830. And all of the Netherlands used to be part of the Spanish and Frence empires....
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Historically, Belgium, the Netherlands and Luxembourg (along with parts of Northern France and Western Germany) were known as the Low Countries; it once covered a somewhat larger area than the current Benelux group of states. The region was called Belgica in Latin, after the Roman province of Gallia Belgica. From the end of the Middle Ages until the 17th century, the area of Belgium was a prosperous and cosmopolitan centre of commerce and culture. From the 16th century until the Belgian Revolution in 1830, when Belgium seceded from the Netherlands, the area of Belgium served as the battleground between many European powers, causing it to be dubbed the "Battlefield of Europe," a reputation strengthened by both world wars.
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With the armed support of revolutionary France, Dutch republicans proclaimed the Batavian Republic, modelled after the French Republic and rendering the Netherlands a unitary state on 19 January 1795. The stadtholder William V of Orange had fled to England. But from 1806 to 1810, the Kingdom of Holland was set up by Napoleon Bonaparte as a puppet kingdom governed by his brother Louis Bonaparte to control the Netherlands more effectively. However, King Louis Bonaparte tried to serve Dutch interests instead of his brother's, and he was forced to abdicate on 1 July 1810. The Emperor sent in an army and the Netherlands became part of the French Empire until the autumn of 1813, when Napoleon was defeated in the Battle of Leipzig. The south gained independence in 1830 as Belgium, while the personal union between Luxembourg and the Netherlands was severed in 1890, when William III died with no surviving male heirs. Ascendancy laws prevented his daughter Queen Wilhelmina from becoming the next Grand Duchess.
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- The name 'Belgium' is derived from Gallia Belgica, a Roman province in the northernmost part of Gaul that before Roman invasion in 100 BC, was inhabited by the Belgae, a mix of Celtic and Germanic peoples. A gradual immigration by Germanic Frankish tribes during the 5th century brought the area under the rule of the Merovingian kings. A gradual shift of power during the 8th century led the kingdom of the Franks to evolve into the Carolingian Empire.
- The Treaty of Verdun in 843 divided the region into Middle and West Francia and therefore into a set of more or less independent fiefdoms which, during the Middle Ages, were vassals either of the King of France or of the Holy Roman Emperor
- The Eighty Years' War (1568–1648) divided the Low Countries into the northern United Provinces (Belgica Foederata in Latin, the "Federated Netherlands") and the Southern Netherlands (Belgica Regia, the "Royal Netherlands"). The latter were ruled successively by the Spanish (Spanish Netherlands) and the Austrian Habsburgs (Austrian Netherlands) and comprised most of modern Belgium. This was the theatre of most Franco-Spanish and Franco-Austrian wars during the 17th and 18th centuries.
- Following the campaigns of 1794 in the French Revolutionary Wars, the Low Countries—including territories that were never nominally under Habsburg rule, such as the Prince-Bishopric of Liège—were annexed by the French First Republic, ending Austrian rule in the region. The reunification of the Low Countries as the United Kingdom of the Netherlands occurred at the dissolution of the First French Empire in 1815, after the defeat of Napoleon.
- In 1830, the Belgian Revolution led to the separation of the Southern Provinces from the Netherlands and to the establishment of a Catholic and bourgeois, officially French-speaking and neutral, independent Belgium under a provisional government and a national congress
The distribution of the primary Germanic dialect groups in Europe in around AD 1:
- Blue North Germanic
- Red North Sea Germanic, or Ingvaeonic
- Orange Weser-Rhine Germanic, or Istvaeonic
- Yellow Elbe Germanic, or Irminonic
- Green East Germanic
14th century
Netherlands Today
Belgium Today
Don't blab about that which you don't know.
Please, I seem to be at least aware of the disintegration of virtually all multi-ethnic states in history.
Look at the examples of Yugoslavia and Czech Republic in just Europe. Soviet Union is another example.
Scoring a cheap point with a wall of text is not befitting of a TTA.