Willem Lodewijk, William Louis, (1560-1620) became Stadholder in Friesland in 1584, in Groningen in 1594 and some years later in Drenthe. In this study - based on archival sources in and outside The Netherlands - the author will try to describe life and work of this German count in the context of their time. Important are the formative years in Germany as Jan van Nassau, William's father and brother of William the Silent, was a staunch supporter of Calvinism, defender of the Union of Utrecht and one of the founders of the 'Hochschule' in Herborn. Important themes in this book will be the tension between the stadholder's position as a 'servant of the Frisian States' and and his background as a count, patronage, court life (numbers of 'courtiers' and noblemen, the court as centre for military study, cultural life, etc.), Willem Lodewijk and Maurits as military leaders, and the stadholder as tutor religionis.