Rubuta ci gaba ga wannan sakin layi - A 1671 Frederick Louis ya zama cornet a cikin rundunar sojan doki von Eller a cikin sojojin Brandenburg-Prussia. A shekara ta 1675 ya shiga cikin yakin Fehrbellin.
a matsayin Rittmeister. A shekara mai zuwa ya kasance colonel a cikin Holstein dragoons. An kira Frederick Louis a matsayin Lieutenant General da Gwamna na Wesel a shekara ta 1690. Shekaru uku bayan haka aka nada shi babban kwamandan Janar na Duchy na Prussia.