Kammala jumla mai zuwa: A matsayin Gwamna Janar ya umurci sojojin Sweden a 1675/76 a kan sojojin Jamus da ke kawance a lokacin yakin Bremen-Verden, amma daga karshe ya mika wuya. An ba shi umurnin Royal Swedish Navy a 1677 kuma an sanya shi memba na Privy Council na Sweden ("riksråd"). A wannan shekarar, Denmark ta doke shi a gasar cin kofin duniya.
Yaƙin Køge Bay a lokacin Yakin Scanian. An nada shi shugaban Kwalejin Amiralities a shekara ta 1677. A shekara ta 1678, an nada shi a matsayin Babban Kwamandan Livonia wanda ya kasance mulkin daular Sweden daga 1629 zuwa 1721. A cikin 1680, Horn ya bar Livonia kuma ya dawo don taimakawa sake gina Stade wanda aka kewaye shi a 1676 yayin Yakin Sweden-Brandenburg.