Most of the area that is modern Belgium was first under one ruler in the 1300s, under the Dukes of Burgundy. This was the Flemish golden age - cloth merchants and weavers brought riches to cities such as Brugge, Ypres and Gent. As the waterways of Brugge became silted up, Antwerpen took over as the main port.
Through marriages etc, the 17 Burgundian provinces (roughly modern day Belgium and the Netherlands) passed to Habsburg Austria, and then in the early 1500s they became part of the Spanish Habsburg Empire. As a result of the reformation, divisions and war flared up within the region. Many Protestant Flemish fled north to Amsterdam and other cities. Eventually, in 1648 (the Treaty of Munster), Spain recognised the independence of the United Provinces of the Netherlands, while the Catholic Low Countries or Spanish Netherlands remained under Spanish rule.
After various wars, the Spanish Netherlands passed back to the Austrian Habsburgs in 1713 (the Treaty of Utrecht). Under Napoleon, the French annexed the Belgian states.
In the early 1800s, Belgium became one of the first countries in mainland Europe to undergo the industrial revolution. Because of its iron ore and coal, Wallonia overtook Flanders as the most prosperous region.
At the congress of Vienna in 1815, William of Orange, who had recently become King of the Netherlands, was given the Low Countries. In both Flanders and Wallonia, French had been the language of the ruling classes throughout the time under foreign rule. In this new country, Dutch was to be the language of the central administration but the King was forced to cave in to the French-speaking elite of the Belgian states.
For religious and linguistic reasons, Dutch rule was not popular. In August 1830 the Belgians revolted and independence was declared on 27 September. After gaining independence, the new country suffered from political conflicts between those for whom it was a traditional Catholic community and those for whom it was a progressive, liberal society.
French was the natural administrative language in this country which had rebelled against Dutch masters. However, there was also a Flemish radical movement which supported the use of Dutch. There was no standard Flemish language, so discussions took place over whether standard Dutch should be adopted, or whether a specifically Flemish standard should be created. Eventually the integrationists won.
Political and socio-economic changes have gradually raised the status of Flemish in Flanders. In 1932 it was officially declared to be a monolingual Dutch-speaking area. In recent years, as the mining industries based in Wallonia have declined, Flanders has once again become the economically dominant part of the country.