The document discusses the growth of power of the Catholic Church during the Middle Ages in Europe. It describes how various reforms strengthened the papacy's authority, such as Pope Leo IX's efforts in the 11th century to eliminate corruption among clergy. This brought the papacy into conflict with political rulers over the appointment of bishops. A key event was the dispute between Pope Gregory VII and Holy Roman Emperor Henry IV, where the pope excommunicated the emperor, asserting the church's independence. Monasticism also saw changes as new orders like the Cistercians embraced more austere lifestyles.