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.
West Frisians The West Frisians (German: "Westfriesen" ) – or, more precisely, the Westlauwers Frisians – are those Frisian peoples in that part of Frisia administered by the Netherlands: the Province of Friesland, which is bounded in the west by the IJsselmeer and in the east by the River Lauwers (hence the name "Westlauwers", i.e., "west of the Lauwers").