The collapse of the Roman Empire sparked a new age of apathy towards knowledge. This age would become known as the Dark Ages. Knowledge no longer became important and as a result most of Europe became ignorant. The only institution that kept books and records of knowledge was the Christian/Catholic church. Power transferred from Rome to feudal societies and the church will play a paramount role throughout Medieval Europe. The church will later unite feudal Europe in a sequence of wars called the “Crusades” to retake the holy land from the Muslim faith Islam. After the failure of the Crusades trade will reopen and become a vital part to Europe. A number of technological advancements from China and the Muslim world would turn Europe towards knowledge again. However, a disease known as the Bubonic Plague will make its way from China to Europe wiping out 1/3 of the population of Europe marking the end of the Medieval Age.