Hessian War died out, and peaked after 1645 in the Hessian War proper. This open warfare began with the Siege of Marburg in 1645 and ended in April 1648 (but before the Treaty of Westphalia which was concluded later that year and ended the Thirty Years' War) with victory going to Hesse-Cassel. In the aftermath, Upper Hesse was divided and parts of its territory went to the now stronger Hesse-Cassel. At a European level the Hessian War must be viewed in the larger context of the Thirty Years' War, in which the reformed Hesse-Cassel sided with the Protestant Swedish party, whilst Hesse-Darmstadt,
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