Nyora kupfuurira kweiyi ndima - Ernest akarerwa somuCalvinist mukati meHondo Yamakore Makumi Matatu. Akaita Grand Tour yake kuFrance neItaly, uye akarwa neHesse-Kassel mumakore ekupedzisira ehondo, semuenzaniso paHondo yeNördlingen
musi wa3 August 1645. Muna 1647, mauto aLandgravine Amalie Elisabeth akakundazve Lower Katzenelnbogen ndokuidzorera kuHesse-Kassel. Muna 1649, Ernest akasvika pazera uye akagamuchira Lower Katzenelnbogen. Ikoku kwakamuita muvambi womutsara weHesse-Rheinfels. Hesse-Rheinfels haina kunzi ine hurumende: yakaramba iri pasi pehurumende yeHesse-Kassel, sezvakaitwa nedzimwe nzvimbo dzeRotenburg Quarter. Tsananguro yehukama pakati peHesse-Rheinfels neHesse-Kassel yakagadzwa mune akateedzana ezvibvumirano zvedzimba; zvisinei, kukakavadzana kwezvematongerwo enyika uye kwepamutemo kwaiwanzomuka pakati peimba mbiri.