John Ernest van Nassau-Siegen

Hereditary Count John Ernest of Nassau-Siegen, German: Johann Ernst Erbgraf von Nassau-Siegen, official titles: Graf zu Nassau, Katzenelnbogen, Vianden und Diez, Herr zu Beilstein, was since 1607 Hereditary Count of Nassau-Siegen, a part of the County of Nassau. He descended from the House of Nassau-Siegen, a cadet branch of the Ottonian Line of the House of Nassau. He first served as an officer in the Dutch States Army and later as general in the Republic of Venice during the Uskok War.