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?
Guelders Guelders or Gueldres (Dutch: "Gelre" , German: "Geldern" ) is a historical county, later duchy of the Holy Roman Empire, located in the Low Countries.
Landgrave Landgrave (Dutch: "landgraaf" , German: "Landgraf" ; Swedish: "lantgreve" , French: "landgrave" ; Latin: "comes magnus" , "comes patriae ", "comes provinciae ", "comes terrae ", "comes principalis ", "lantgravius ") was a noble title used in the Holy Roman Empire, and later on in its former territories. The German titles of "Landgraf ", "Markgraf " ("margrave"), and "Pfalzgraf " ("count palatine") are in the same class of ranks as "Herzog " ("duke") and above the rank of a "Graf " ("count").