An opposing political faction in Rome tried to force the anti-pope Sergius III onto the throne, but failed.
John called several synods in his short time, all of which supported orthodox Christianity and condemned the works of outlaw synods.
Prohibited the custom of pludering the palaces of recently deceasedbishops.
Supported Lambert as Emperor.
His synod at Ravenna called for actions by civil authorities to curb increasing violence.
Sanctioned the creation of bishops in Moravia which kept them politically independent of German authorities.