Kammala jumla mai zuwa: A karkashin mulkin Frederick William II mai rauni (1786-.1797) Prussia ta sami mummunan koma baya na tattalin arziki, siyasa da soja. Sarkin da ya gaje shi Frederick William III ya yi ƙoƙari ya kasance mai tsaka tsaki a lokacin Yaƙin Ƙungiya ta Uku da kuma Sarkin Faransa Napoleon ya rushe Daular Roman Mai Tsarki da sake fasalin masarautun Jamus. Sarauniyar da kuma jam'iyyar da ke goyon bayan yakin Frederick William ya shiga cikin
Hadin gwiwar na huɗu a watan Oktoba 1806. Napoleon ya sauƙaƙe sojojin Prussian a Yaƙin Jena kuma ya mamaye Berlin. Prussia ta rasa yankunan da ta samu kwanan nan a yammacin Jamus, an rage sojojinsa zuwa maza 42,000, ba a ba da izinin kasuwanci tare da Burtaniya ba kuma Berlin ta biya Paris babbar diyya da kuma tallafawa sojojin Faransa na mamayewa. Saxony ya canza bangarorin don tallafawa Napoleon kuma ya shiga cikin Confederation na Rhine. An ba wa mai mulki Frederick Augustus I kyautar sarauta kuma aka ba shi yanki na Poland da aka karɓa daga Prussia.