Gonzalez, Justo L. The Story of Christianity: The Early Church to the Reformation. Revised and Updated ed. Vol. 1. New York: HarperCollins, 2010. Kindle Electronic Edition.
Ch. 30, “Movements of Renewal” Loc. 5712-6025.
As the Carolingian Empire declined Gonzalez sees a new desire for order (Gonzalez 2010, Loc. 5712). Because many reform-minded people had joined the monastic movement, much reform later came from that sector (Gonzalez 2010, Loc. 5720). In the early 10th century the monastery at Cluny was dedicated as a reform-minded community (Gonzalez 2010, Loc. 5741). The reforms were centered around the Rule of St. Benedict and observance of the liturgical hours (Gonzalez 2010, Loc. 5752). The movement spread to promote clerical celibacy as a rule, not simply a common lifestyle (Gonzalez 2010, Loc. 5780). The Cistercian movement arose in the late 11th century. Its prominent leader was Bernard of Clairvaux, “at once the mystic devoted to the contemplation of the humanity of Christ, the power behind and above the papacy . . . the champion of ecclesiastical reform, the preacher of the Second Crusade, and the enemy of all theological innovation” (Gonzalez 2010, Loc. 5819).
Another attempt at reform began in the mid 11th century, when there were legislative attempts to use Canon law for papal reform (Gonzalez 2010, Loc. 5830). By the work of Pope Leo IX much reformation of simony and a move for priestly celibacy was made (Gonzalez 2010, Loc. 5862). By 1070 there were moves by Gregory VII to end simony, require a celibate clergy, and to seek the return of the Eastern church (Gonzalez 2010, Loc. 5893).
Under Emperor Henry IV the empire and papacy came into conflict (Gonzalez 2010, Loc. 5914). The emperor wished to appoint bishops who would support him while the pope wanted support from the emperor. There was a military engagement late in 1075 followed by a popular revolt against the emperor in Rome. Both pope and emperor deposed one another (Gonzalez 2010, Loc. 5924). There followed several interactions of formal forgiveness followed by hostility. By 1081 Gregory was in exile, the Normans took Rome for Henry, and the subsequent situation became increasingly politicized (Gonzalez 2010, Loc. 5956). Gonzalez summarizes a number of these clashes prior to a cessation of many hostilities in 1122 (Gonzalez 2010, Loc. 5997).