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.
Rhine Province The Rhine Province (German: "Rheinprovinz" ), also known as Rhenish Prussia ("Rheinpreußen") or synonymous with the Rhineland ("Rheinland"), was the westernmost province of the Kingdom of Prussia and the Free State of Prussia, within the German Reich, from 1822 to 1946. It was created from the provinces of the Lower Rhine and Jülich-Cleves-Berg. Its capital was Koblenz and in 1939 it had 8 million inhabitants. The Province of Hohenzollern was militarily associated with the Oberpräsident of the Rhine Province.