Guibert attended the first Lenten Synods of Pope Gregory in March 1074 in Rome at which important laws were passed against simony and the incontinence of the clergy, but he soon emerged as one of the most visible leaders of opposition to the Gregorian reforms.
Guibert asistiu ao concilio coresmal do papa Gregorio en marzo de 1074 levado a cabo en Roma, onde importantes leis foron en contra da simonía e da incontinencia do clero, pero pronto emerxeu como un dos líderes da oposición das reformas gregorianas.