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.
William II de La Marck William II de la Marck (Lummen, 1542 – Bishopric of Liège, 1 May 1578) (Dutch: "Willem II van der Marck") was Lord of Lumey and initially admiral of the Watergeuzen, the so-called 'sea beggars' who fought in the Eighty Years' War (1568–1648), together with among others William the Silent, Prince of Orange-Nassau. He was the great-grandson of an equally notorious character, baron William de la Marck, nicknamed the "wild boar of the Ardennes".