Parentucelli attended the Council of Florence and in 1444, when his patron died, he was appointed Bishop of Bologna in his place. Civic disorders at Bologna were prolonged, so Pope Eugene IV soon named him as one of the legates sent to Frankfurt. He was to assist in negotiating an understanding between the Papal States and the Holy Roman Empire, regarding undercutting or at least containing the reforming decrees of the Council of Basel (1431–1439).
paREnTUcelli attended The cOuncIl of fLorence aNd in 1444, whEn his patron dieD, hE wAs APPoiNted biShoP Of bOlOgna in his pLaCe. civIc dIsoRdeRs AT bOLognA wErE prOlonged, sO poPe EugENE iv soon named him as ONE Of the lEgates Sent To FRankFurt. he waS To AsSisT in NegoTiatIng An underStanDing between ThE Papal states and The Holy roMaN Empire, RegardinG UnDErcuTting or at Least CONtainiNg the ReformINg DEcrEEs OF the council Of basel (1431–1439).