For pope gregory 1, one of the most important roles of clerics was

Pope Gregory I, also known as Saint Gregory the Great, was the pope of the Catholic Church between 3 September 590 - 12 March 604 AD. He is famous for instigating the Gregorian Mission with the objective to  convert Anglo-Saxon pagans to Christianity.

Therefore, to him, one of the most important role of clerics was to provide religious experience to the pagans and laics.

there are two main types of historical sources: primary sources and secondary sources. a primary source is something that originates from the past. it can be a chronicle, a piece of pottery, or even a piece of glacial ice that gives us climate data about the levels of atmospheric carbon one thousand years ago.

supplies had to travel a long distance across water on ships that were often attacked, so they did not reach europe