Lokacin da Novgorodiyawa suka juya zuwa Poland-Lithuania don taimako don iyakance ikon girma na Moscow, Ivan III da babban birni sun zarge su ba kawai da yaudarar siyasa ba, amma na ƙoƙarin yin watsi da Orthodoxy na Gabas kuma su wuce zuwa Cocin Katolika.Daftarin yarjejeniya tsakanin Novgorod da Grand Duke na Lithuania da Sarkin Poland, Casimir IV Jagiellon (r. 1440-1492), an ce an same shi a cikin tarin takardu bayan yakin Shelon, ya bayyana a fili cewa Grand Lithuania Prince ba zai tsoma baki tare da zaben babban Bishop na Novgorod ko bangaskiyar Orthodox a cikin birnin ba (ta hanyar gina cocin Katolika a birnin misali).Yakin Shelon wani gagarumin yaki ne tsakanin sojojin Grand Duchy na Moscow karkashin Ivan III da sojojin Jamhuriyar Novgorod, wanda ya faru a kan kogin Shelon a ranar 14 ga Yuli 1471. Novgorod ya sha wahala sosai kuma ya ƙare tare da de de. gaskiya mika wuya na birnin ba tare da wani sharadi ba.Muscovy ya mamaye Novgorod a 1478.