Though there had been conflict between the Papacy and the Roman Empire about Lay Investiture for the better part of the century, the true beginning of the investiture controversy, when Pope Gregory VII and Emperor Henry IV declared open opposition, was in the year of 1075 when Gregory VII wrote the Decree against Lay Investiture.
Thus, the basis of the conflict: Pope Gregory VII and his Reform Catholics believed the right of anointing bishops to belong to the Pope and the Pope alone while Emperor Henry IV wanted to keep the power split between the papacy and the empire to assure that he lost no ground to the new, hostile papacy.
