1. He made strides to reform the government of the Church and make it independent from Roman nobles as well as secular rulers. He set up a body of high Church prelates at Rome to advise him and play the central role in future nomination of Popes. This 'College of Cardinals' he stacked with close reforming colleagues, such as Hildebrand, who had already served as Papal secretary; and Humbert, a leading ideologue of Church reform.
2. Leo initiated a ruthless campaign against clerical corruption in the form of marriage and simony. After a series of synods in Rome that legislated against such abuses, he, like a feudal monarch, traveled throughout Europe, holding court in the major diocese centers. From the spring to fall of 1049, he went throughout Italy, Germany, and France. At Reims in particular, anti-simony and anti-clerical marriage decrees were published, accusations against prelates were heard, and clerics were challenged to swear before the Pope that they had not purchased their offices. Several were deposed, replaced by more reform-oriented clergy. Thus, by the death of Leo's successor in 1057, the leadership of the Papacy as secular-moral judge of the Church was finally firmly established among most clerics.
By 1057, the last of Henry III's popes was dead, as was he. His son Henry IV was under a regency headed by his mother, and Roman reformers seized the opportunity to elect a Pope themselves, without consulting the regents, who weakly consented to the election. The same was the case for the election of Nicholas II in 1059. His short three-year pontificate exhibited measures of great significance for the rest of the century of Papal-German relations. First was a 1059 council in Rome, the purpose of which was to secure to the Papacy alone the power to appoint upper-level clergy. The first step was the pontificate itself. At the council an important decree regulating the conduct of papal elections held that only the College of Cardinals could elect a pope, thereby sidelining both Roman lay notables and German Emperors. Broad statements indicating that a priest was not to receive a church from a layman were also included here.
Nicholas second action of great significance was taken to protect popes against those who opposed the new electoral procedure. Basically, he needed muscle to protect his claims, and so he turned to the Normans of southern Italy. In the early 1000s, a group of Norman knights returning from pilgrimage to the East found the political vacuum of south-central Italy congenial to their desire for raiding and political aggrandizement, as their minor lord status at home would block further advancement there. Through the 1030s, the sons of Tancred de Hauteville worked mostly as mercenaries for hire, but soon they began taking lands for themselves. When the oldest son William died in 1046, he had control of Apulia. Soon, more of Tancred's sons arrived, most notably Robert Guiscard and his brother, Roger. Between 1057-1071 Robert was able to eliminate Byzantine positions in Italy, eventually occupying Bari. Moving to Muslim Sicily, Robert and Roger combined to take Palermo in 1072, with Roger conquering the entirety of the island by the 1190s. This was all-important for the Papacy because in 1059 Pope Nicholas recognized Robert Guiscard as Duke of Apulia and Calabria, receiving homage in return and a pledge of protection. Thus, the Pope felt he had acquired military support for his spiritual agenda.
Nicholas died in 1061, and in line with the new electoral terms, the College of Cardinals elected Alexander II as pope. A reformer, he was supported by the Normans, and was recognized two years later by German bishops and imperial regents. For the next twelve years until 1073, the Papacy was able to consolidate its authority over European churches, overseeing the implementation of reform decrees. During this same time, the forces of conflict were maturing. Henry IV (1056-1106) was coming into his maturity and needed to turn back the processes of princely usurpation of the crown's powers and authority. One way was to obtain the support of Germany's bishops through appointing them. He did not want the Pope--whom he had not appointed--to tell him who to invest as bishop and who was impermissible. Only royal power's needs should govern this, Henry thought, and for the same reason he did not want to imperil his clerics' support by insisting on reform and clerical celibacy. Already he had conflicted with Rome, when Alexander had excommunicated royal ministers for simony. Also, the Papacy and the Emperor were supporting opposing candidates for the bishopric of Milan. As the bishop here was also civil ruler, Henry needed his man there if ever he was to reestablish authority in Italy.
The conflict came to a head with the election of Hildebrand as Pope Gregory VII in 1073. He was an arch-reformer, feeling that he was God's vicar on earth and that all clerics of Latin Christianity should be responsible to him, and him alone. At best, secular rulers were only the mundane, profane instruments to achieve ecclesiastically defined goals. Immediately upon coming to power, he wrote Henry IV, telling him to mind his own business regarding Milan. Facing a revolt by Saxon, Bavarian, and Swabian dukes, Henry had to defer. Then, in 1075, Gregory threw down the gauntlet. At a Rome synod, he read the Papal decree Dictatus Papae. Its key points were 1) The Roman Church was founded by god and so not subject to any secular government; 2) only the Church, under the Pope, could call a council; 3) only God could judge a Pope; 4) only the Pope could invest or depose bishops; and 5) the Pope could depose kings and Emperors, freeing their subjects from allegiance to them. At the same time he claimed that no one invested by a layman was a real bishop, and that any non-cleric who would presume to do such a thing would be excommunicated. Basically, the Papacy was to be totally in charge of every aspect of the ecclesiastical structure of Europe. This was revolutionary in its clear articulation, as it went to the core of the prevalent theories of kingship, and interfered with feudal governmental practices. It appears that Gregory wanted to create a papal monarchy with the pope at its head. At the least, he wanted to draw a radical line between church and state. This was inimical to German governance going back to the Ottos if not before. This conflict became known as the Investiture Controversy.