Following a struggle against the Spanish Habsburg empire, the northern (Dutch) part of the Low Countries won full independence in 1648 and became a leading imperial power. In 1814 north and south were united under a monarchy, but the south revolted in 1830 and became an independent kingdom, Belgium, in 1839. In 1948 the Netherlands formed the Benelux Customs Union with Belgium and Luxembourg, becoming a founder member of the EEC in 1957. The name Holland strictly refers only to the western coastal provinces of the country.