The Rise of the Papacy - Free download as Word Doc (.doc), PDF File (.pdf), Text File (.txt) or read online for free. 1. In the late 4th century, Emperor Theodosius declared Christianity the official religion of the Roman Empire and bishops established a hierarchy with the Pope of Rome at the top, beginning the rise of papal authority. 2. After the fall of the Western Roman Empire in the 5th century, the papacy seized the opportunity to gain more power and influence by becoming the guardian of civilization and order in the chaos. 3. In the 8th century, Charlemagne was crowned emperor by the Pope, further solidifying the relationship between royal power and the Roman Church and strengthening the papacy's authority in Western Europe.