What is the name of the historical county, later duchy of the Holy Roman Empire, located in the Low Countries that  Adolf van Nieuwenaar worked for in the  Eighty Years' War?
Adolf van Nieuwenaar Adolf van Nieuwenaar, Count of Limburg and Moers (also: Adolf von Neuenahr) (c. 1545 – 18 October 1589) was a statesman and soldier, who was stadtholder of Overijssel, Guelders and Utrecht for the States-General of the Netherlands during the Eighty Years' War.
South Limburg (Netherlands) South Limburg (Dutch: "Zuid-Limburg", Limburgish: "Zuud-Limburg") is both a COROP (statistical) region as well as a "landstreek" (area) of the Netherlands located in the province of Limburg. The Dutch term "landstreek", literally translated "land area/region", means that the area is not an administrative region but an area that displays cohesion with regard to culture and landscape. With regards to South Limburg this deals with its hilly landscape, especially in the Heuvelland region, sunken lanes, an abundance of castles, and the regional language Limburgish spoken by a significant part of the population alongside Dutch. The region also contains the highest point above sea level in mainland Netherlands, the Vaalserberg being 322.5 m above sea level (the highest point of the entire country is in the Caribbean Netherlands' island of Saba, namely Mount Scenery being 887 m above sea level).