High Quality Content by WIKIPEDIA articles! John Maurice of Nassau (17 June 1604 20 December 1679) was count and (from 1674) prince of Nassau-Siegen. He was born in Dillenburg. His father was John VII of Nassau, his grandfather John VI of Nassau, the younger brother of Dutch stadtholder William the Silent of Orange. John Maurice joined the Dutch army in 1621, at a very early age. He distinguished himself in the campaigns of his cousin, the stadtholder Frederick Henry, Prince of Orange. In 1626 he became captain. He was involved in 1629 in the capture of Den Bosch. In 1636, he conquered a fortress at Schenkenschans.