The High Middle Ages was a time of considerable expansion and reformation of Christendom

The High Middle Ages was a time of considerable expansion and reformation of Christendom. By Expansion, it is meant that the physical borders of Christendom were expanded through the conquest of other lands. Various reforms, Particularly the Gregorian Reform, aimed at the purification of the church and society is what is meant by using the word Reformation. Both the expansion and reformation can be seen in the accounts of the speech that Pope Urban II Gave at the Council of Clermont.
Christendom is the fusion of Christianity and society that began to happen during the reign of Constantine. By the High middle ages, there was hardly any distinction between the two. When the Holy Roman Empire expanded territorially it was thought that Christianity was being expanded. The word Christendom is not mentioned in either of the two accounts of Urban’s speech, but the concept is seen quite clearly. Fulcher’s account of the speech says that the Turks had attacked the brethren in the east, in the Roman territory, and devastated the kingdom of God (Sources, p. 338). After connecting those living in the Roman territory with the kingdom of God, He goes on to say that the Turks, from outside of Christendom, are a vile people “despised, degenerate, and slaves of the demons (Sources, p. 339).” In Robert’s account of the speech, while encouraging the Franks to embark on the first crusade, Pope Urban II reminds them of the deeds of Charlemagne and the other Frankish kings who “destroyed the kingdom of the pagans,” and “extended in these lands the territory of the Holy Church (Sources, p. 339, 340).” This correlation between the brethren living in the Roman territory and Christianity, not to mention the contrast between the pagan Turks and the brethren living in the east, points to this idea of Christendom.
In his speech, Pope Urban II was encouraging the Frankish men to go on a crusade and fight the Turks, thus expanding Christendom. From these accounts, it seems that Urban gave two major reasons why the men should do this. The First reason was the expansion of Christendom. There was a desire to free the Holy Land (particularly Jerusalem) from captivity and retake the land that had previously been invaded by the Turks (Sources, p. 338, 340). The Byzantine Empire had been deprived of vast territory and Urban knew that if the Turks were left unopposed they would continue to extend their sway over Christendom (Sources, p. 339, 338). The second major reason for the First Crusade was to provide help and relief to the people who had been conquered by the Turks. The Turks had killed and captured many of the Christians and horrible reports of torture were coming back from the east (Sources, p. 338, 339)
The reform of Christendom is also seen in Pope Urban’s speech. In Fulcher’s account Urban begins his discourse admonishing his hearers to show themselves to be faithful servants of God and to correct themselves so that they may be able to correct those under their charge (Sources p. 337,338). The influence of Gregorian reform is seen when he tells his hearers to be sure to obey the church rules so that simoniacal heresy would not take root among them (Sources, p. 338). Simoniacal heresy or simony, was when someone paid to obtain a church office which was a source of untold corruption in the church. Pope Gregory VII was a major opponent of simony and started a movement that sought to purify the church and clergy known as the Gregorian Reform. Urban also tried to reform Christendom by reenacting the law made by their ancestors called the Truce of God (Sources, p. 338).
There is evidence from these two accounts of both an expansion and reformation of Christendom in the High Middle Ages. At this time the pope had lots of power. The result of Pope Urban’s speech led to the First Crusade and set a pattern for the crusades that followed, considerably impacting the course of the history of western civilization.