conquer the Holy Land, the Papacy endowed the Normans with the crusader spirit, thereby boosting their morale and their reputation as they embarked on proto-crusades to win back lands for Western Christendom. In order to consolidate their conquests, the Normans had to manipulate the Church in Italy and Sicily, founding and endowing religious institutions and appointing their friends as bishops and abbots. The popes cooperated with the Normans in this, because the Normans subjected the Greek Christians of their realms to the authority of the Apostolic See and upheld the standards of the Gregorian reform movement.
The Papacy and the Normans reached an accord whereby the Pope held the Normans' loyalty in his battle with King Henry IV of Germany, and the Normans had the privilege of filling ecclesiastical posts with their supporters, thereby expanding their influence throughout their realms. This agreement made the Norman conquests possible, and simultaneously kept the Gregorian reform movement alive in spite of severe opposition from Germany and elsewhere. Central to the alliance was the concept of chivalry, which the Papacy instilled in the Normans to put their marauding spirit to good use. Their desire to invade Italy and Sicily and establish themselves in these new territories reflects their Viking heritage. The Papacy saw in this desire an opportunity to expand and strengthen its influence, and so it blessed the Normans and declared their conquests (most of them, at least) sacred and just, which made the Normans seem more legitimate in the eyes of their subjects and in the eyes of other European rulers. The Papacy also recognized the advantage it would have over the German Emperor if it had the mighty Norman knights on its side, so the Normans in Italy received sanctioned titles