From Academic Kids
The Low Countries, the historical region of de Nederlanden, are the countries (see "Country") on low-lying land around the delta of the Rhine, Scheldt, and Meuse (Maas) rivers. The term is not particularly current in modern contexts because the region does not very exactly correspond with the nation-states The Netherlands, Belgium and Luxembourg, for which an alternate term, the Benelux was applied after World War II. .
Prior to early modern nationbuilding, the Low Countries referred to a wide area of northern Europe roughly stretching from Dunkirk at its south-western point to the area of Schleswig-Holstein at its north-eastern point, from the estuary of the Scheldt in the south to Frisia in the north. The Low Countries were the scene of the early northern towns, built from scratch rather than developed from ancient centers, that mark the reawakening of Europe in the 12th century. Cities of the Early Middle Ages built round the manufacture and trade of woollen cloth, Europe's first industry, included Liège, Leuven, Mechelen, Antwerp, Brussels, Ypres, Ghent and Utrecht, to employ a list compiled by Henri Pirenne.
In 1477 the Burgundian holdings in the area, the Burgundian Netherlands passed through an heiress Mary of Burgundy to the Habsburgs. In the following century the "Low Countries" corresponded roughly to the Seventeen Provinces covered by the Pragmatic Sanction of 1549 of Holy Roman Emperor Charles V, which freed the provinces from their archaic feudal obligations. After the Seventeen Provinces declared their independence from Habsburg Spain, the provinces of the Southern Netherlands were recaptured (1581) and are sometimes called the Spanish Netherlands.
In 1713, under the Treaty of Utrecht following the War of the Spanish Succession, what was left of the Spanish Netherlands was ceded to Austria and thus became known as the Austrian Netherlands. The United Kingdom of the Netherlands (1815-1830) temporarily united the Low Countries again.
To distinguish between the older, larger Netherlands from the current country, Dutch speakers usually drop the plural for the nation. They speak of Nederland for the modern nation and de Nederlanden for the domains of Charles V.