Medieval Flanders was a slice of France that France never got back
In the Middle Ages the rich cloth cities of Ghent, Bruges and Ypres belonged to the Kingdom of France, and the Count of Flanders ranked among the original twelve peers of the realm. Today most of that county lies in Belgium. Only one other part of medieval France, Catalonia, has similarly slipped away for good.
The County of Flanders hugged the North Sea coast of what is now Belgium and north-eastern France, and its trading towns, including Lille, made it one of Europe's wealthiest regions, with commercial ties reaching far abroad. Its heartland lay west of the river Scheldt under French overlordship, which historians call Royal Flanders. From the 11th century the counts also ruled lands on the Scheldt's far bank, which they held from the German emperors and which is known as Imperial Flanders, so they answered to two masters at once.
That balance tipped away from France over time. From 1384 Flanders was bound to the Duchy of Burgundy and became the launch pad for Burgundian expansion across the Low Countries. When the Habsburgs inherited those lands in 1477, the imperial link grew stronger, and treaties in 1526 and 1529 brought most of Flanders into the empire under the Spanish Habsburg crown. Revolutionary France seized the region by 1795, but after Waterloo in 1815 it went to the new United Kingdom of the Netherlands, which split between 1830 and 1839 into Belgium, the Netherlands and Luxembourg. The Belgians revived the old names, which is why two western provinces are now called West and East Flanders.
The name first appears in a life of Saint Eligius, written before 684, mentioning a place in Flandris near Bruges. In 1948 Maurits Gysseling proposed that it grew from a Proto-Germanic word for stream or flood, suggesting a term for waterlogged land. That would suit a coast of salt marsh and mudflat, regularly flooded until dyke-building began around 1050, although the required word forms never appear in any Dutch records.
The old county is now scattered across several countries and languages: Belgian provinces, a corner of Hainaut, French Flanders around Dunkirk, where Flemish was once the main tongue, and a southern strip where Picard was spoken.
Source: County of Flanders
