The Old Swiss Confederacy a "de facto" independent state throughout the early modern period, although still nominally part of the Holy Roman Empire until 1648 when the Treaty of Westphalia ended the Thirty Years' War. The Swiss Reformation divided the confederates into Reformed and Catholic parties, resulting in internal conflict from the 16th to the 18th centuries; as a result, the federal diet () was often paralysed by hostility between the factions. The Swiss Confederacy fell to invasion by the French Revolutionary Army in 1798, after which it became the short-lived Helvetic Republic. The adjective "old" was introduced after the Napoleonic era with ,
Seventeen Provinces during the Eighty Years' War (see Generality Lands), which ended with the Treaty of Westphalia in 1648. Artois and parts of Flanders and Hainaut (French Flanders and French Hainaut) were ceded to France in the course of the 17th and 18th centuries. By the mid-16th century, the Margraviate of Antwerp (Duchy of Brabant) had become the economic, political, and cultural center of the Netherlands after its capital had shifted from the nearby Lordship of Mechelen to the city of Brussels. Bruges (County of Flanders) had already lost its prominent position as economic powerhouse of northern Europe. And Holland was gradually